clearml-agent/clearml_agent/_vendor/ruamel/yaml/constructor.py

# coding: utf-8

import datetime
import base64
import binascii
import sys
import types
import warnings
from collections.abc import Hashable, MutableSequence, MutableMapping

# fmt: off
from ...._vendor.ruamel.yaml.error import (MarkedYAMLError, MarkedYAMLFutureWarning,
                               MantissaNoDotYAML1_1Warning)
from ...._vendor.ruamel.yaml.nodes import *                               # NOQA
from ...._vendor.ruamel.yaml.nodes import (SequenceNode, MappingNode, ScalarNode)
from ...._vendor.ruamel.yaml.compat import (builtins_module, # NOQA
                                nprint, nprintf, version_tnf)
from ...._vendor.ruamel.yaml.compat import ordereddict

from ...._vendor.ruamel.yaml.tag import Tag
from ...._vendor.ruamel.yaml.comments import *                               # NOQA
from ...._vendor.ruamel.yaml.comments import (CommentedMap, CommentedOrderedMap, CommentedSet,
                                  CommentedKeySeq, CommentedSeq, TaggedScalar,
                                  CommentedKeyMap,
                                  C_KEY_PRE, C_KEY_EOL, C_KEY_POST,
                                  C_VALUE_PRE, C_VALUE_EOL, C_VALUE_POST,
                                  )
from ...._vendor.ruamel.yaml.scalarstring import (SingleQuotedScalarString, DoubleQuotedScalarString,
                                      LiteralScalarString, FoldedScalarString,
                                      PlainScalarString, ScalarString)
from ...._vendor.ruamel.yaml.scalarint import ScalarInt, BinaryInt, OctalInt, HexInt, HexCapsInt
from ...._vendor.ruamel.yaml.scalarfloat import ScalarFloat
from ...._vendor.ruamel.yaml.scalarbool import ScalarBoolean
from ...._vendor.ruamel.yaml.timestamp import TimeStamp
from ...._vendor.ruamel.yaml.util import timestamp_regexp, create_timestamp

from typing import Any, Dict, List, Set, Iterator, Union, Optional  # NOQA


__all__ = ['BaseConstructor', 'SafeConstructor', 'Constructor',
           'ConstructorError', 'RoundTripConstructor']
# fmt: on


class ConstructorError(MarkedYAMLError):
    pass


class DuplicateKeyFutureWarning(MarkedYAMLFutureWarning):
    pass


class DuplicateKeyError(MarkedYAMLError):
    pass


class BaseConstructor:

    yaml_constructors = {}  # type: Dict[Any, Any]
    yaml_multi_constructors = {}  # type: Dict[Any, Any]

    def __init__(self, preserve_quotes: Optional[bool] = None, loader: Any = None) -> None:
        self.loader = loader
        if self.loader is not None and getattr(self.loader, '_constructor', None) is None:
            self.loader._constructor = self
        self.loader = loader
        self.yaml_base_dict_type = dict
        self.yaml_base_list_type = list
        self.constructed_objects: Dict[Any, Any] = {}
        self.recursive_objects: Dict[Any, Any] = {}
        self.state_generators: List[Any] = []
        self.deep_construct = False
        self._preserve_quotes = preserve_quotes
        self.allow_duplicate_keys = version_tnf((0, 15, 1), (0, 16))

    @property
    def composer(self) -> Any:
        if hasattr(self.loader, 'typ'):
            return self.loader.composer
        try:
            return self.loader._composer
        except AttributeError:
            sys.stdout.write(f'slt {type(self)}\n')
            sys.stdout.write(f'slc {self.loader._composer}\n')
            sys.stdout.write(f'{dir(self)}\n')
            raise

    @property
    def resolver(self) -> Any:
        if hasattr(self.loader, 'typ'):
            return self.loader.resolver
        return self.loader._resolver

    @property
    def scanner(self) -> Any:
        # needed to get to the expanded comments
        if hasattr(self.loader, 'typ'):
            return self.loader.scanner
        return self.loader._scanner

    def check_data(self) -> Any:
        # If there are more documents available?
        return self.composer.check_node()

    def get_data(self) -> Any:
        # Construct and return the next document.
        if self.composer.check_node():
            return self.construct_document(self.composer.get_node())

    def get_single_data(self) -> Any:
        # Ensure that the stream contains a single document and construct it.
        node = self.composer.get_single_node()
        if node is not None:
            return self.construct_document(node)
        return None

    def construct_document(self, node: Any) -> Any:
        data = self.construct_object(node)
        while bool(self.state_generators):
            state_generators = self.state_generators
            self.state_generators = []
            for generator in state_generators:
                for _dummy in generator:
                    pass
        self.constructed_objects = {}
        self.recursive_objects = {}
        self.deep_construct = False
        return data

    def construct_object(self, node: Any, deep: bool = False) -> Any:
        """deep is True when creating an object/mapping recursively,
        in that case want the underlying elements available during construction
        """
        if node in self.constructed_objects:
            return self.constructed_objects[node]
        if deep:
            old_deep = self.deep_construct
            self.deep_construct = True
        if node in self.recursive_objects:
            return self.recursive_objects[node]
            # raise ConstructorError(
            #     None, None, 'found unconstructable recursive node', node.start_mark
            # )
        self.recursive_objects[node] = None
        data = self.construct_non_recursive_object(node)

        self.constructed_objects[node] = data
        del self.recursive_objects[node]
        if deep:
            self.deep_construct = old_deep
        return data

    def construct_non_recursive_object(self, node: Any, tag: Optional[str] = None) -> Any:
        constructor: Any = None
        tag_suffix = None
        if tag is None:
            tag = node.tag
        if tag in self.yaml_constructors:
            constructor = self.yaml_constructors[tag]
        else:
            for tag_prefix in self.yaml_multi_constructors:
                if tag.startswith(tag_prefix):
                    tag_suffix = tag[len(tag_prefix) :]
                    constructor = self.yaml_multi_constructors[tag_prefix]
                    break
            else:
                if None in self.yaml_multi_constructors:
                    tag_suffix = tag
                    constructor = self.yaml_multi_constructors[None]
                elif None in self.yaml_constructors:
                    constructor = self.yaml_constructors[None]
                elif isinstance(node, ScalarNode):
                    constructor = self.__class__.construct_scalar
                elif isinstance(node, SequenceNode):
                    constructor = self.__class__.construct_sequence
                elif isinstance(node, MappingNode):
                    constructor = self.__class__.construct_mapping
        if tag_suffix is None:
            data = constructor(self, node)
        else:
            data = constructor(self, tag_suffix, node)
        if isinstance(data, types.GeneratorType):
            generator = data
            data = next(generator)
            if self.deep_construct:
                for _dummy in generator:
                    pass
            else:
                self.state_generators.append(generator)
        return data

    def construct_scalar(self, node: Any) -> Any:
        if not isinstance(node, ScalarNode):
            raise ConstructorError(
                None, None, f'expected a scalar node, but found {node.id!s}', node.start_mark,
            )
        return node.value

    def construct_sequence(self, node: Any, deep: bool = False) -> Any:
        """deep is True when creating an object/mapping recursively,
        in that case want the underlying elements available during construction
        """
        if not isinstance(node, SequenceNode):
            raise ConstructorError(
                None,
                None,
                f'expected a sequence node, but found {node.id!s}',
                node.start_mark,
            )
        return [self.construct_object(child, deep=deep) for child in node.value]

    def construct_mapping(self, node: Any, deep: bool = False) -> Any:
        """deep is True when creating an object/mapping recursively,
        in that case want the underlying elements available during construction
        """
        if not isinstance(node, MappingNode):
            raise ConstructorError(
                None, None, f'expected a mapping node, but found {node.id!s}', node.start_mark,
            )
        total_mapping = self.yaml_base_dict_type()
        if getattr(node, 'merge', None) is not None:
            todo = [(node.merge, False), (node.value, False)]
        else:
            todo = [(node.value, True)]
        for values, check in todo:
            mapping: Dict[Any, Any] = self.yaml_base_dict_type()
            for key_node, value_node in values:
                # keys can be list -> deep
                key = self.construct_object(key_node, deep=True)
                # lists are not hashable, but tuples are
                if not isinstance(key, Hashable):
                    if isinstance(key, list):
                        key = tuple(key)
                if not isinstance(key, Hashable):
                    raise ConstructorError(
                        'while constructing a mapping',
                        node.start_mark,
                        'found unhashable key',
                        key_node.start_mark,
                    )

                value = self.construct_object(value_node, deep=deep)
                if check:
                    if self.check_mapping_key(node, key_node, mapping, key, value):
                        mapping[key] = value
                else:
                    mapping[key] = value
            total_mapping.update(mapping)
        return total_mapping

    def check_mapping_key(
        self, node: Any, key_node: Any, mapping: Any, key: Any, value: Any,
    ) -> bool:
        """return True if key is unique"""
        if key in mapping:
            if not self.allow_duplicate_keys:
                mk = mapping.get(key)
                args = [
                    'while constructing a mapping',
                    node.start_mark,
                    f'found duplicate key "{key}" with value "{value}" '
                    f'(original value: "{mk}")',
                    key_node.start_mark,
                    """
                    To suppress this check see:
                        http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys
                    """,
                    """\
                    Duplicate keys will become an error in future releases, and are errors
                    by default when using the new API.
                    """,
                ]
                if self.allow_duplicate_keys is None:
                    warnings.warn(DuplicateKeyFutureWarning(*args), stacklevel=1)
                else:
                    raise DuplicateKeyError(*args)
            return False
        return True

    def check_set_key(self: Any, node: Any, key_node: Any, setting: Any, key: Any) -> None:
        if key in setting:
            if not self.allow_duplicate_keys:
                args = [
                    'while constructing a set',
                    node.start_mark,
                    f'found duplicate key "{key}"',
                    key_node.start_mark,
                    """
                    To suppress this check see:
                        http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys
                    """,
                    """\
                    Duplicate keys will become an error in future releases, and are errors
                    by default when using the new API.
                    """,
                ]
                if self.allow_duplicate_keys is None:
                    warnings.warn(DuplicateKeyFutureWarning(*args), stacklevel=1)
                else:
                    raise DuplicateKeyError(*args)

    def construct_pairs(self, node: Any, deep: bool = False) -> Any:
        if not isinstance(node, MappingNode):
            raise ConstructorError(
                None, None, f'expected a mapping node, but found {node.id!s}', node.start_mark,
            )
        pairs = []
        for key_node, value_node in node.value:
            key = self.construct_object(key_node, deep=deep)
            value = self.construct_object(value_node, deep=deep)
            pairs.append((key, value))
        return pairs

    # ToDo: putting stuff on the class makes it global, consider making this to work on an
    # instance variable once function load is dropped.
    @classmethod
    def add_constructor(cls, tag: Any, constructor: Any) -> Any:
        if isinstance(tag, Tag):
            tag = str(tag)
        if 'yaml_constructors' not in cls.__dict__:
            cls.yaml_constructors = cls.yaml_constructors.copy()
        ret_val = cls.yaml_constructors.get(tag, None)
        cls.yaml_constructors[tag] = constructor
        return ret_val

    @classmethod
    def add_multi_constructor(cls, tag_prefix: Any, multi_constructor: Any) -> None:
        if 'yaml_multi_constructors' not in cls.__dict__:
            cls.yaml_multi_constructors = cls.yaml_multi_constructors.copy()
        cls.yaml_multi_constructors[tag_prefix] = multi_constructor

    @classmethod
    def add_default_constructor(
        cls, tag: str, method: Any = None, tag_base: str = 'tag:yaml.org,2002:',
    ) -> None:
        if not tag.startswith('tag:'):
            if method is None:
                method = 'construct_yaml_' + tag
            tag = tag_base + tag
        cls.add_constructor(tag, getattr(cls, method))


class SafeConstructor(BaseConstructor):
    def construct_scalar(self, node: Any) -> Any:
        if isinstance(node, MappingNode):
            for key_node, value_node in node.value:
                if key_node.tag == 'tag:yaml.org,2002:value':
                    return self.construct_scalar(value_node)
        return BaseConstructor.construct_scalar(self, node)

    def flatten_mapping(self, node: Any) -> Any:
        """
        This implements the merge key feature http://yaml.org/type/merge.html
        by inserting keys from the merge dict/list of dicts if not yet
        available in this node
        """
        merge: List[Any] = []
        index = 0
        while index < len(node.value):
            key_node, value_node = node.value[index]
            if key_node.tag == 'tag:yaml.org,2002:merge':
                if merge:  # double << key
                    if self.allow_duplicate_keys:
                        del node.value[index]
                        index += 1
                        continue
                    args = [
                        'while constructing a mapping',
                        node.start_mark,
                        f'found duplicate key "{key_node.value}"',
                        key_node.start_mark,
                        """
                        To suppress this check see:
                           http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys
                        """,
                        """\
                        Duplicate keys will become an error in future releases, and are errors
                        by default when using the new API.
                        """,
                    ]
                    if self.allow_duplicate_keys is None:
                        warnings.warn(DuplicateKeyFutureWarning(*args), stacklevel=1)
                    else:
                        raise DuplicateKeyError(*args)
                del node.value[index]
                if isinstance(value_node, MappingNode):
                    self.flatten_mapping(value_node)
                    merge.extend(value_node.value)
                elif isinstance(value_node, SequenceNode):
                    submerge = []
                    for subnode in value_node.value:
                        if not isinstance(subnode, MappingNode):
                            raise ConstructorError(
                                'while constructing a mapping',
                                node.start_mark,
                                f'expected a mapping for merging, but found {subnode.id!s}',
                                subnode.start_mark,
                            )
                        self.flatten_mapping(subnode)
                        submerge.append(subnode.value)
                    submerge.reverse()
                    for value in submerge:
                        merge.extend(value)
                else:
                    raise ConstructorError(
                        'while constructing a mapping',
                        node.start_mark,
                        'expected a mapping or list of mappings for merging, '
                        f'but found {value_node.id!s}',
                        value_node.start_mark,
                    )
            elif key_node.tag == 'tag:yaml.org,2002:value':
                key_node.tag = 'tag:yaml.org,2002:str'
                index += 1
            else:
                index += 1
        if bool(merge):
            node.merge = merge  # separate merge keys to be able to update without duplicate
            node.value = merge + node.value

    def construct_mapping(self, node: Any, deep: bool = False) -> Any:
        """deep is True when creating an object/mapping recursively,
        in that case want the underlying elements available during construction
        """
        if isinstance(node, MappingNode):
            self.flatten_mapping(node)
        return BaseConstructor.construct_mapping(self, node, deep=deep)

    def construct_yaml_null(self, node: Any) -> Any:
        self.construct_scalar(node)
        return None

    # YAML 1.2 spec doesn't mention yes/no etc any more, 1.1 does
    bool_values = {
        'yes': True,
        'no': False,
        'y': True,
        'n': False,
        'true': True,
        'false': False,
        'on': True,
        'off': False,
    }

    def construct_yaml_bool(self, node: Any) -> bool:
        value = self.construct_scalar(node)
        return self.bool_values[value.lower()]

    def construct_yaml_int(self, node: Any) -> int:
        value_s = self.construct_scalar(node)
        value_s = value_s.replace('_', "")
        sign = +1
        if value_s[0] == '-':
            sign = -1
        if value_s[0] in '+-':
            value_s = value_s[1:]
        if value_s == '0':
            return 0
        elif value_s.startswith('0b'):
            return sign * int(value_s[2:], 2)
        elif value_s.startswith('0x'):
            return sign * int(value_s[2:], 16)
        elif value_s.startswith('0o'):
            return sign * int(value_s[2:], 8)
        elif self.resolver.processing_version == (1, 1) and value_s[0] == '0':
            return sign * int(value_s, 8)
        elif self.resolver.processing_version == (1, 1) and ':' in value_s:
            digits = [int(part) for part in value_s.split(':')]
            digits.reverse()
            base = 1
            value = 0
            for digit in digits:
                value += digit * base
                base *= 60
            return sign * value
        else:
            return sign * int(value_s)

    inf_value = 1e300
    while inf_value != inf_value * inf_value:
        inf_value *= inf_value
    nan_value = -inf_value / inf_value  # Trying to make a quiet NaN (like C99).

    def construct_yaml_float(self, node: Any) -> float:
        value_so = self.construct_scalar(node)
        value_s = value_so.replace('_', "").lower()
        sign = +1
        if value_s[0] == '-':
            sign = -1
        if value_s[0] in '+-':
            value_s = value_s[1:]
        if value_s == '.inf':
            return sign * self.inf_value
        elif value_s == '.nan':
            return self.nan_value
        elif self.resolver.processing_version != (1, 2) and ':' in value_s:
            digits = [float(part) for part in value_s.split(':')]
            digits.reverse()
            base = 1
            value = 0.0
            for digit in digits:
                value += digit * base
                base *= 60
            return sign * value
        else:
            if self.resolver.processing_version != (1, 2) and 'e' in value_s:
                # value_s is lower case independent of input
                mantissa, exponent = value_s.split('e')
                if '.' not in mantissa:
                    warnings.warn(MantissaNoDotYAML1_1Warning(node, value_so), stacklevel=1)
            return sign * float(value_s)

    def construct_yaml_binary(self, node: Any) -> Any:
        try:
            value = self.construct_scalar(node).encode('ascii')
        except UnicodeEncodeError as exc:
            raise ConstructorError(
                None,
                None,
                f'failed to convert base64 data into ascii: {exc!s}',
                node.start_mark,
            )
        try:
            return base64.decodebytes(value)
        except binascii.Error as exc:
            raise ConstructorError(
                None, None, f'failed to decode base64 data: {exc!s}', node.start_mark,
            )

    timestamp_regexp = timestamp_regexp  # moved to util 0.17.17

    def construct_yaml_timestamp(self, node: Any, values: Any = None) -> Any:
        if values is None:
            try:
                match = self.timestamp_regexp.match(node.value)
            except TypeError:
                match = None
            if match is None:
                raise ConstructorError(
                    None,
                    None,
                    f'failed to construct timestamp from "{node.value}"',
                    node.start_mark,
                )
            values = match.groupdict()
        return create_timestamp(**values)

    def construct_yaml_omap(self, node: Any) -> Any:
        # Note: we do now check for duplicate keys
        omap = ordereddict()
        yield omap
        if not isinstance(node, SequenceNode):
            raise ConstructorError(
                'while constructing an ordered map',
                node.start_mark,
                f'expected a sequence, but found {node.id!s}',
                node.start_mark,
            )
        for subnode in node.value:
            if not isinstance(subnode, MappingNode):
                raise ConstructorError(
                    'while constructing an ordered map',
                    node.start_mark,
                    f'expected a mapping of length 1, but found {subnode.id!s}',
                    subnode.start_mark,
                )
            if len(subnode.value) != 1:
                raise ConstructorError(
                    'while constructing an ordered map',
                    node.start_mark,
                    f'expected a single mapping item, but found {len(subnode.value):d} items',
                    subnode.start_mark,
                )
            key_node, value_node = subnode.value[0]
            key = self.construct_object(key_node)
            assert key not in omap
            value = self.construct_object(value_node)
            omap[key] = value

    def construct_yaml_pairs(self, node: Any) -> Any:
        # Note: the same code as `construct_yaml_omap`.
        pairs: List[Any] = []
        yield pairs
        if not isinstance(node, SequenceNode):
            raise ConstructorError(
                'while constructing pairs',
                node.start_mark,
                f'expected a sequence, but found {node.id!s}',
                node.start_mark,
            )
        for subnode in node.value:
            if not isinstance(subnode, MappingNode):
                raise ConstructorError(
                    'while constructing pairs',
                    node.start_mark,
                    f'expected a mapping of length 1, but found {subnode.id!s}',
                    subnode.start_mark,
                )
            if len(subnode.value) != 1:
                raise ConstructorError(
                    'while constructing pairs',
                    node.start_mark,
                    f'expected a single mapping item, but found {len(subnode.value):d} items',
                    subnode.start_mark,
                )
            key_node, value_node = subnode.value[0]
            key = self.construct_object(key_node)
            value = self.construct_object(value_node)
            pairs.append((key, value))

    def construct_yaml_set(self, node: Any) -> Any:
        data: Set[Any] = set()
        yield data
        value = self.construct_mapping(node)
        data.update(value)

    def construct_yaml_str(self, node: Any) -> Any:
        value = self.construct_scalar(node)
        return value

    def construct_yaml_seq(self, node: Any) -> Any:
        data: List[Any] = self.yaml_base_list_type()
        yield data
        data.extend(self.construct_sequence(node))

    def construct_yaml_map(self, node: Any) -> Any:
        data: Dict[Any, Any] = self.yaml_base_dict_type()
        yield data
        value = self.construct_mapping(node)
        data.update(value)

    def construct_yaml_object(self, node: Any, cls: Any) -> Any:
        data = cls.__new__(cls)
        yield data
        if hasattr(data, '__setstate__'):
            state = self.construct_mapping(node, deep=True)
            data.__setstate__(state)
        else:
            state = self.construct_mapping(node)
            data.__dict__.update(state)

    def construct_undefined(self, node: Any) -> None:
        raise ConstructorError(
            None,
            None,
            f'could not determine a constructor for the tag {node.tag!r}',
            node.start_mark,
        )


for tag in 'null bool int float binary timestamp omap pairs set str seq map'.split():
    SafeConstructor.add_default_constructor(tag)

SafeConstructor.add_constructor(None, SafeConstructor.construct_undefined)


class Constructor(SafeConstructor):
    def construct_python_str(self, node: Any) -> Any:
        return self.construct_scalar(node)

    def construct_python_unicode(self, node: Any) -> Any:
        return self.construct_scalar(node)

    def construct_python_bytes(self, node: Any) -> Any:
        try:
            value = self.construct_scalar(node).encode('ascii')
        except UnicodeEncodeError as exc:
            raise ConstructorError(
                None,
                None,
                f'failed to convert base64 data into ascii: {exc!s}',
                node.start_mark,
            )
        try:
            return base64.decodebytes(value)
        except binascii.Error as exc:
            raise ConstructorError(
                None, None, f'failed to decode base64 data: {exc!s}', node.start_mark,
            )

    def construct_python_long(self, node: Any) -> int:
        val = self.construct_yaml_int(node)
        return val

    def construct_python_complex(self, node: Any) -> Any:
        return complex(self.construct_scalar(node))

    def construct_python_tuple(self, node: Any) -> Any:
        return tuple(self.construct_sequence(node))

    def find_python_module(self, name: Any, mark: Any) -> Any:
        if not name:
            raise ConstructorError(
                'while constructing a Python module',
                mark,
                'expected non-empty name appended to the tag',
                mark,
            )
        try:
            __import__(name)
        except ImportError as exc:
            raise ConstructorError(
                'while constructing a Python module',
                mark,
                f'cannot find module {name!r} ({exc!s})',
                mark,
            )
        return sys.modules[name]

    def find_python_name(self, name: Any, mark: Any) -> Any:
        if not name:
            raise ConstructorError(
                'while constructing a Python object',
                mark,
                'expected non-empty name appended to the tag',
                mark,
            )
        if '.' in name:
            lname = name.split('.')
            lmodule_name = lname
            lobject_name: List[Any] = []
            while len(lmodule_name) > 1:
                lobject_name.insert(0, lmodule_name.pop())
                module_name = '.'.join(lmodule_name)
                try:
                    __import__(module_name)
                    # object_name = '.'.join(object_name)
                    break
                except ImportError:
                    continue
        else:
            module_name = builtins_module
            lobject_name = [name]
        try:
            __import__(module_name)
        except ImportError as exc:
            raise ConstructorError(
                'while constructing a Python object',
                mark,
                f'cannot find module {module_name!r} ({exc!s})',
                mark,
            )
        module = sys.modules[module_name]
        object_name = '.'.join(lobject_name)
        obj = module
        while lobject_name:
            if not hasattr(obj, lobject_name[0]):

                raise ConstructorError(
                    'while constructing a Python object',
                    mark,
                    f'cannot find {object_name!r} in the module {module.__name__!r}',
                    mark,
                )
            obj = getattr(obj, lobject_name.pop(0))
        return obj

    def construct_python_name(self, suffix: Any, node: Any) -> Any:
        value = self.construct_scalar(node)
        if value:
            raise ConstructorError(
                'while constructing a Python name',
                node.start_mark,
                f'expected the empty value, but found {value!r}',
                node.start_mark,
            )
        return self.find_python_name(suffix, node.start_mark)

    def construct_python_module(self, suffix: Any, node: Any) -> Any:
        value = self.construct_scalar(node)
        if value:
            raise ConstructorError(
                'while constructing a Python module',
                node.start_mark,
                f'expected the empty value, but found {value!r}',
                node.start_mark,
            )
        return self.find_python_module(suffix, node.start_mark)

    def make_python_instance(
        self, suffix: Any, node: Any, args: Any = None, kwds: Any = None, newobj: bool = False,
    ) -> Any:
        if not args:
            args = []
        if not kwds:
            kwds = {}
        cls = self.find_python_name(suffix, node.start_mark)
        if newobj and isinstance(cls, type):
            return cls.__new__(cls, *args, **kwds)
        else:
            return cls(*args, **kwds)

    def set_python_instance_state(self, instance: Any, state: Any) -> None:
        if hasattr(instance, '__setstate__'):
            instance.__setstate__(state)
        else:
            slotstate: Dict[Any, Any] = {}
            if isinstance(state, tuple) and len(state) == 2:
                state, slotstate = state
            if hasattr(instance, '__dict__'):
                instance.__dict__.update(state)
            elif state:
                slotstate.update(state)
            for key, value in slotstate.items():
                setattr(instance, key, value)

    def construct_python_object(self, suffix: Any, node: Any) -> Any:
        # Format:
        #   !!python/object:module.name { ... state ... }
        instance = self.make_python_instance(suffix, node, newobj=True)
        self.recursive_objects[node] = instance
        yield instance
        deep = hasattr(instance, '__setstate__')
        state = self.construct_mapping(node, deep=deep)
        self.set_python_instance_state(instance, state)

    def construct_python_object_apply(
        self, suffix: Any, node: Any, newobj: bool = False,
    ) -> Any:
        # Format:
        #   !!python/object/apply       # (or !!python/object/new)
        #   args: [ ... arguments ... ]
        #   kwds: { ... keywords ... }
        #   state: ... state ...
        #   listitems: [ ... listitems ... ]
        #   dictitems: { ... dictitems ... }
        # or short format:
        #   !!python/object/apply [ ... arguments ... ]
        # The difference between !!python/object/apply and !!python/object/new
        # is how an object is created, check make_python_instance for details.
        if isinstance(node, SequenceNode):
            args = self.construct_sequence(node, deep=True)
            kwds: Dict[Any, Any] = {}
            state: Dict[Any, Any] = {}
            listitems: List[Any] = []
            dictitems: Dict[Any, Any] = {}
        else:
            value = self.construct_mapping(node, deep=True)
            args = value.get('args', [])
            kwds = value.get('kwds', {})
            state = value.get('state', {})
            listitems = value.get('listitems', [])
            dictitems = value.get('dictitems', {})
        instance = self.make_python_instance(suffix, node, args, kwds, newobj)
        if bool(state):
            self.set_python_instance_state(instance, state)
        if bool(listitems):
            instance.extend(listitems)
        if bool(dictitems):
            for key in dictitems:
                instance[key] = dictitems[key]
        return instance

    def construct_python_object_new(self, suffix: Any, node: Any) -> Any:
        return self.construct_python_object_apply(suffix, node, newobj=True)

    @classmethod
    def add_default_constructor(
        cls, tag: str, method: Any = None, tag_base: str = 'tag:yaml.org,2002:python/',
    ) -> None:
        if not tag.startswith('tag:'):
            if method is None:
                method = 'construct_yaml_' + tag
            tag = tag_base + tag
        cls.add_constructor(tag, getattr(cls, method))


Constructor.add_constructor('tag:yaml.org,2002:python/none', Constructor.construct_yaml_null)

Constructor.add_constructor('tag:yaml.org,2002:python/bool', Constructor.construct_yaml_bool)

Constructor.add_constructor('tag:yaml.org,2002:python/str', Constructor.construct_python_str)

Constructor.add_constructor(
    'tag:yaml.org,2002:python/unicode', Constructor.construct_python_unicode,
)

Constructor.add_constructor(
    'tag:yaml.org,2002:python/bytes', Constructor.construct_python_bytes,
)

Constructor.add_constructor('tag:yaml.org,2002:python/int', Constructor.construct_yaml_int)

Constructor.add_constructor('tag:yaml.org,2002:python/long', Constructor.construct_python_long)

Constructor.add_constructor('tag:yaml.org,2002:python/float', Constructor.construct_yaml_float)

Constructor.add_constructor(
    'tag:yaml.org,2002:python/complex', Constructor.construct_python_complex,
)

Constructor.add_constructor('tag:yaml.org,2002:python/list', Constructor.construct_yaml_seq)

Constructor.add_constructor(
    'tag:yaml.org,2002:python/tuple', Constructor.construct_python_tuple,
)
# for tag in 'bool str unicode bytes int long float complex tuple'.split():
#    Constructor.add_default_constructor(tag)

Constructor.add_constructor('tag:yaml.org,2002:python/dict', Constructor.construct_yaml_map)

Constructor.add_multi_constructor(
    'tag:yaml.org,2002:python/name:', Constructor.construct_python_name,
)

Constructor.add_multi_constructor(
    'tag:yaml.org,2002:python/module:', Constructor.construct_python_module,
)

Constructor.add_multi_constructor(
    'tag:yaml.org,2002:python/object:', Constructor.construct_python_object,
)

Constructor.add_multi_constructor(
    'tag:yaml.org,2002:python/object/apply:', Constructor.construct_python_object_apply,
)

Constructor.add_multi_constructor(
    'tag:yaml.org,2002:python/object/new:', Constructor.construct_python_object_new,
)


class RoundTripConstructor(SafeConstructor):
    """need to store the comments on the node itself,
    as well as on the items
    """

    def comment(self, idx: Any) -> Any:
        assert self.loader.comment_handling is not None
        x = self.scanner.comments[idx]
        x.set_assigned()
        return x

    def comments(self, list_of_comments: Any, idx: Optional[Any] = None) -> Any:
        # hand in the comment and optional pre, eol, post segment
        if list_of_comments is None:
            return []
        if idx is not None:
            if list_of_comments[idx] is None:
                return []
            list_of_comments = list_of_comments[idx]
        for x in list_of_comments:
            yield self.comment(x)

    def construct_scalar(self, node: Any) -> Any:
        if not isinstance(node, ScalarNode):
            raise ConstructorError(
                None, None, f'expected a scalar node, but found {node.id!s}', node.start_mark,
            )

        if node.style == '|' and isinstance(node.value, str):
            lss = LiteralScalarString(node.value, anchor=node.anchor)
            if self.loader and self.loader.comment_handling is None:
                if node.comment and node.comment[1]:
                    lss.comment = node.comment[1][0]  # type: ignore
            else:
                # NEWCMNT
                if node.comment is not None and node.comment[1]:
                    # nprintf('>>>>nc1', node.comment)
                    # EOL comment after |
                    lss.comment = self.comment(node.comment[1][0])  # type: ignore
            return lss
        if node.style == '>' and isinstance(node.value, str):
            fold_positions: List[int] = []
            idx = -1
            while True:
                idx = node.value.find('\a', idx + 1)
                if idx < 0:
                    break
                fold_positions.append(idx - len(fold_positions))
            fss = FoldedScalarString(node.value.replace('\a', ''), anchor=node.anchor)
            if self.loader and self.loader.comment_handling is None:
                if node.comment and node.comment[1]:
                    fss.comment = node.comment[1][0]  # type: ignore
            else:
                # NEWCMNT
                if node.comment is not None and node.comment[1]:
                    # nprintf('>>>>nc2', node.comment)
                    # EOL comment after >
                    fss.comment = self.comment(node.comment[1][0])  # type: ignore
            if fold_positions:
                fss.fold_pos = fold_positions  # type: ignore
            return fss
        elif bool(self._preserve_quotes) and isinstance(node.value, str):
            if node.style == "'":
                return SingleQuotedScalarString(node.value, anchor=node.anchor)
            if node.style == '"':
                return DoubleQuotedScalarString(node.value, anchor=node.anchor)
        # if node.ctag:
        #     data2 = TaggedScalar()
        #     data2.value = node.value
        #     data2.style = node.style
        #     data2.yaml_set_ctag(node.ctag)
        #     if node.anchor:
        #         from ruamel.yaml.serializer import templated_id

        #         if not templated_id(node.anchor):
        #             data2.yaml_set_anchor(node.anchor, always_dump=True)
        #     return data2
        if node.anchor:
            return PlainScalarString(node.value, anchor=node.anchor)
        return node.value

    def construct_yaml_int(self, node: Any) -> Any:
        width: Any = None
        value_su = self.construct_scalar(node)
        try:
            sx = value_su.rstrip('_')
            underscore: Any = [len(sx) - sx.rindex('_') - 1, False, False]
        except ValueError:
            underscore = None
        except IndexError:
            underscore = None
        value_s = value_su.replace('_', "")
        sign = +1
        if value_s[0] == '-':
            sign = -1
        if value_s[0] in '+-':
            value_s = value_s[1:]
        if value_s == '0':
            return 0
        elif value_s.startswith('0b'):
            if self.resolver.processing_version > (1, 1) and value_s[2] == '0':
                width = len(value_s[2:])
            if underscore is not None:
                underscore[1] = value_su[2] == '_'
                underscore[2] = len(value_su[2:]) > 1 and value_su[-1] == '_'
            return BinaryInt(
                sign * int(value_s[2:], 2),
                width=width,
                underscore=underscore,
                anchor=node.anchor,
            )
        elif value_s.startswith('0x'):
            # default to lower-case if no a-fA-F in string
            if self.resolver.processing_version > (1, 1) and value_s[2] == '0':
                width = len(value_s[2:])
            hex_fun: Any = HexInt
            for ch in value_s[2:]:
                if ch in 'ABCDEF':  # first non-digit is capital
                    hex_fun = HexCapsInt
                    break
                if ch in 'abcdef':
                    break
            if underscore is not None:
                underscore[1] = value_su[2] == '_'
                underscore[2] = len(value_su[2:]) > 1 and value_su[-1] == '_'
            return hex_fun(
                sign * int(value_s[2:], 16),
                width=width,
                underscore=underscore,
                anchor=node.anchor,
            )
        elif value_s.startswith('0o'):
            if self.resolver.processing_version > (1, 1) and value_s[2] == '0':
                width = len(value_s[2:])
            if underscore is not None:
                underscore[1] = value_su[2] == '_'
                underscore[2] = len(value_su[2:]) > 1 and value_su[-1] == '_'
            return OctalInt(
                sign * int(value_s[2:], 8),
                width=width,
                underscore=underscore,
                anchor=node.anchor,
            )
        elif self.resolver.processing_version != (1, 2) and value_s[0] == '0':
            return OctalInt(
                sign * int(value_s, 8), width=width, underscore=underscore, anchor=node.anchor,
            )
        elif self.resolver.processing_version != (1, 2) and ':' in value_s:
            digits = [int(part) for part in value_s.split(':')]
            digits.reverse()
            base = 1
            value = 0
            for digit in digits:
                value += digit * base
                base *= 60
            return sign * value
        elif self.resolver.processing_version > (1, 1) and value_s[0] == '0':
            # not an octal, an integer with leading zero(s)
            if underscore is not None:
                # cannot have a leading underscore
                underscore[2] = len(value_su) > 1 and value_su[-1] == '_'
            return ScalarInt(sign * int(value_s), width=len(value_s), underscore=underscore)
        elif underscore:
            # cannot have a leading underscore
            underscore[2] = len(value_su) > 1 and value_su[-1] == '_'
            return ScalarInt(
                sign * int(value_s), width=None, underscore=underscore, anchor=node.anchor,
            )
        elif node.anchor:
            return ScalarInt(sign * int(value_s), width=None, anchor=node.anchor)
        else:
            return sign * int(value_s)

    def construct_yaml_float(self, node: Any) -> Any:
        def leading_zeros(v: Any) -> int:
            lead0 = 0
            idx = 0
            while idx < len(v) and v[idx] in '0.':
                if v[idx] == '0':
                    lead0 += 1
                idx += 1
            return lead0

        # underscore = None
        m_sign: Any = False
        value_so = self.construct_scalar(node)
        value_s = value_so.replace('_', "").lower()
        sign = +1
        if value_s[0] == '-':
            sign = -1
        if value_s[0] in '+-':
            m_sign = value_s[0]
            value_s = value_s[1:]
        if value_s == '.inf':
            return sign * self.inf_value
        if value_s == '.nan':
            return self.nan_value
        if self.resolver.processing_version != (1, 2) and ':' in value_s:
            digits = [float(part) for part in value_s.split(':')]
            digits.reverse()
            base = 1
            value = 0.0
            for digit in digits:
                value += digit * base
                base *= 60
            return sign * value
        if 'e' in value_s:
            try:
                mantissa, exponent = value_so.split('e')
                exp = 'e'
            except ValueError:
                mantissa, exponent = value_so.split('E')
                exp = 'E'
            if self.resolver.processing_version != (1, 2):
                # value_s is lower case independent of input
                if '.' not in mantissa:
                    warnings.warn(MantissaNoDotYAML1_1Warning(node, value_so), stacklevel=1)
            lead0 = leading_zeros(mantissa)
            width = len(mantissa)
            prec = mantissa.find('.')
            if m_sign:
                width -= 1
            e_width = len(exponent)
            e_sign = exponent[0] in '+-'
            # nprint('sf', width, prec, m_sign, exp, e_width, e_sign)
            return ScalarFloat(
                sign * float(value_s),
                width=width,
                prec=prec,
                m_sign=m_sign,
                m_lead0=lead0,
                exp=exp,
                e_width=e_width,
                e_sign=e_sign,
                anchor=node.anchor,
            )
        width = len(value_so)
        # you can't use index, !!float 42 would be a float without a dot
        prec = value_so.find('.')
        lead0 = leading_zeros(value_so)
        return ScalarFloat(
            sign * float(value_s),
            width=width,
            prec=prec,
            m_sign=m_sign,
            m_lead0=lead0,
            anchor=node.anchor,
        )

    def construct_yaml_str(self, node: Any) -> Any:
        if node.ctag.handle:
            value = self.construct_unknown(node)
        else:
            value = self.construct_scalar(node)
        if isinstance(value, ScalarString):
            return value
        return value

    def construct_rt_sequence(self, node: Any, seqtyp: Any, deep: bool = False) -> Any:
        if not isinstance(node, SequenceNode):
            raise ConstructorError(
                None,
                None,
                f'expected a sequence node, but found {node.id!s}',
                node.start_mark,
            )
        ret_val = []
        if self.loader and self.loader.comment_handling is None:
            if node.comment:
                seqtyp._yaml_add_comment(node.comment[:2])
                if len(node.comment) > 2:
                    # this happens e.g. if you have a sequence element that is a flow-style
                    # mapping and that has no EOL comment but a following commentline or
                    # empty line
                    seqtyp.yaml_end_comment_extend(node.comment[2], clear=True)
        else:
            # NEWCMNT
            if node.comment:
                nprintf('nc3', node.comment)
        if node.anchor:
            from ...._vendor.ruamel.yaml.serializer import templated_id

            if not templated_id(node.anchor):
                seqtyp.yaml_set_anchor(node.anchor)
        for idx, child in enumerate(node.value):
            if child.comment:
                seqtyp._yaml_add_comment(child.comment, key=idx)
                child.comment = None  # if moved to sequence remove from child
            ret_val.append(self.construct_object(child, deep=deep))
            seqtyp._yaml_set_idx_line_col(
                idx, [child.start_mark.line, child.start_mark.column],
            )
        return ret_val

    def flatten_mapping(self, node: Any) -> Any:
        """
        This implements the merge key feature http://yaml.org/type/merge.html
        by inserting keys from the merge dict/list of dicts if not yet
        available in this node
        """

        def constructed(value_node: Any) -> Any:
            # If the contents of a merge are defined within the
            # merge marker, then they won't have been constructed
            # yet. But if they were already constructed, we need to use
            # the existing object.
            if value_node in self.constructed_objects:
                value = self.constructed_objects[value_node]
            else:
                value = self.construct_object(value_node, deep=True)
            return value

        # merge = []
        merge_map_list: List[Any] = []
        index = 0
        while index < len(node.value):
            key_node, value_node = node.value[index]
            if key_node.tag == 'tag:yaml.org,2002:merge':
                if merge_map_list:  # double << key
                    if self.allow_duplicate_keys:
                        del node.value[index]
                        index += 1
                        continue
                    args = [
                        'while constructing a mapping',
                        node.start_mark,
                        f'found duplicate key "{key_node.value}"',
                        key_node.start_mark,
                        """
                        To suppress this check see:
                           http://yaml.readthedocs.io/en/latest/api.html#duplicate-keys
                        """,
                        """\
                        Duplicate keys will become an error in future releases, and are errors
                        by default when using the new API.
                        """,
                    ]
                    if self.allow_duplicate_keys is None:
                        warnings.warn(DuplicateKeyFutureWarning(*args), stacklevel=1)
                    else:
                        raise DuplicateKeyError(*args)
                del node.value[index]
                if isinstance(value_node, MappingNode):
                    merge_map_list.append((index, constructed(value_node)))
                    # self.flatten_mapping(value_node)
                    # merge.extend(value_node.value)
                elif isinstance(value_node, SequenceNode):
                    # submerge = []
                    for subnode in value_node.value:
                        if not isinstance(subnode, MappingNode):
                            raise ConstructorError(
                                'while constructing a mapping',
                                node.start_mark,
                                f'expected a mapping for merging, but found {subnode.id!s}',
                                subnode.start_mark,
                            )
                        merge_map_list.append((index, constructed(subnode)))
                    #     self.flatten_mapping(subnode)
                    #     submerge.append(subnode.value)
                    # submerge.reverse()
                    # for value in submerge:
                    #     merge.extend(value)
                else:
                    raise ConstructorError(
                        'while constructing a mapping',
                        node.start_mark,
                        'expected a mapping or list of mappings for merging, '
                        f'but found {value_node.id!s}',
                        value_node.start_mark,
                    )
            elif key_node.tag == 'tag:yaml.org,2002:value':
                key_node.tag = 'tag:yaml.org,2002:str'
                index += 1
            else:
                index += 1
        return merge_map_list
        # if merge:
        #     node.value = merge + node.value

    def _sentinel(self) -> None:
        pass

    def construct_mapping(self, node: Any, maptyp: Any, deep: bool = False) -> Any:  # type: ignore # NOQA
        if not isinstance(node, MappingNode):
            raise ConstructorError(
                None, None, f'expected a mapping node, but found {node.id!s}', node.start_mark,
            )
        merge_map = self.flatten_mapping(node)
        # mapping = {}
        if self.loader and self.loader.comment_handling is None:
            if node.comment:
                maptyp._yaml_add_comment(node.comment[:2])
                if len(node.comment) > 2:
                    maptyp.yaml_end_comment_extend(node.comment[2], clear=True)
        else:
            # NEWCMNT
            if node.comment:
                # nprintf('nc4', node.comment, node.start_mark)
                if maptyp.ca.pre is None:
                    maptyp.ca.pre = []
                for cmnt in self.comments(node.comment, 0):
                    maptyp.ca.pre.append(cmnt)
        if node.anchor:
            from ...._vendor.ruamel.yaml.serializer import templated_id

            if not templated_id(node.anchor):
                maptyp.yaml_set_anchor(node.anchor)
        last_key, last_value = None, self._sentinel
        for key_node, value_node in node.value:
            # keys can be list -> deep
            key = self.construct_object(key_node, deep=True)
            # lists are not hashable, but tuples are
            if not isinstance(key, Hashable):
                if isinstance(key, MutableSequence):
                    key_s = CommentedKeySeq(key)
                    if key_node.flow_style is True:
                        key_s.fa.set_flow_style()
                    elif key_node.flow_style is False:
                        key_s.fa.set_block_style()
                    key_s._yaml_set_line_col(key.lc.line, key.lc.col)  # type: ignore
                    key = key_s
                elif isinstance(key, MutableMapping):
                    key_m = CommentedKeyMap(key)
                    if key_node.flow_style is True:
                        key_m.fa.set_flow_style()
                    elif key_node.flow_style is False:
                        key_m.fa.set_block_style()
                    key_m._yaml_set_line_col(key.lc.line, key.lc.col)  # type: ignore
                    key = key_m
            if not isinstance(key, Hashable):
                raise ConstructorError(
                    'while constructing a mapping',
                    node.start_mark,
                    'found unhashable key',
                    key_node.start_mark,
                )
            value = self.construct_object(value_node, deep=deep)
            if self.check_mapping_key(node, key_node, maptyp, key, value):
                if self.loader and self.loader.comment_handling is None:
                    if key_node.comment and len(key_node.comment) > 4 and key_node.comment[4]:
                        if last_value is None:
                            key_node.comment[0] = key_node.comment.pop(4)
                            maptyp._yaml_add_comment(key_node.comment, value=last_key)
                        else:
                            key_node.comment[2] = key_node.comment.pop(4)
                            maptyp._yaml_add_comment(key_node.comment, key=key)
                        key_node.comment = None
                    if key_node.comment:
                        maptyp._yaml_add_comment(key_node.comment, key=key)
                    if value_node.comment:
                        maptyp._yaml_add_comment(value_node.comment, value=key)
                else:
                    # NEWCMNT
                    if key_node.comment:
                        nprintf('nc5a', key, key_node.comment)
                        if key_node.comment[0]:
                            maptyp.ca.set(key, C_KEY_PRE, key_node.comment[0])
                        if key_node.comment[1]:
                            maptyp.ca.set(key, C_KEY_EOL, key_node.comment[1])
                        if key_node.comment[2]:
                            maptyp.ca.set(key, C_KEY_POST, key_node.comment[2])
                    if value_node.comment:
                        nprintf('nc5b', key, value_node.comment)
                        if value_node.comment[0]:
                            maptyp.ca.set(key, C_VALUE_PRE, value_node.comment[0])
                        if value_node.comment[1]:
                            maptyp.ca.set(key, C_VALUE_EOL, value_node.comment[1])
                        if value_node.comment[2]:
                            maptyp.ca.set(key, C_VALUE_POST, value_node.comment[2])
                maptyp._yaml_set_kv_line_col(
                    key,
                    [
                        key_node.start_mark.line,
                        key_node.start_mark.column,
                        value_node.start_mark.line,
                        value_node.start_mark.column,
                    ],
                )
                maptyp[key] = value
                last_key, last_value = key, value  # could use indexing
        # do this last, or <<: before a key will prevent insertion in instances
        # of collections.OrderedDict (as they have no __contains__
        if merge_map:
            maptyp.add_yaml_merge(merge_map)

    def construct_setting(self, node: Any, typ: Any, deep: bool = False) -> Any:
        if not isinstance(node, MappingNode):
            raise ConstructorError(
                None, None, f'expected a mapping node, but found {node.id!s}', node.start_mark,
            )
        if self.loader and self.loader.comment_handling is None:
            if node.comment:
                typ._yaml_add_comment(node.comment[:2])
                if len(node.comment) > 2:
                    typ.yaml_end_comment_extend(node.comment[2], clear=True)
        else:
            # NEWCMNT
            if node.comment:
                nprintf('nc6', node.comment)
        if node.anchor:
            from ...._vendor.ruamel.yaml.serializer import templated_id

            if not templated_id(node.anchor):
                typ.yaml_set_anchor(node.anchor)
        for key_node, value_node in node.value:
            # keys can be list -> deep
            key = self.construct_object(key_node, deep=True)
            # lists are not hashable, but tuples are
            if not isinstance(key, Hashable):
                if isinstance(key, list):
                    key = tuple(key)
            if not isinstance(key, Hashable):
                raise ConstructorError(
                    'while constructing a mapping',
                    node.start_mark,
                    'found unhashable key',
                    key_node.start_mark,
                )
            # construct but should be null
            value = self.construct_object(value_node, deep=deep)  # NOQA
            self.check_set_key(node, key_node, typ, key)
            if self.loader and self.loader.comment_handling is None:
                if key_node.comment:
                    typ._yaml_add_comment(key_node.comment, key=key)
                if value_node.comment:
                    typ._yaml_add_comment(value_node.comment, value=key)
            else:
                # NEWCMNT
                if key_node.comment:
                    nprintf('nc7a', key_node.comment)
                if value_node.comment:
                    nprintf('nc7b', value_node.comment)
            typ.add(key)

    def construct_yaml_seq(self, node: Any) -> Iterator[CommentedSeq]:
        data = CommentedSeq()
        data._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
        # if node.comment:
        #    data._yaml_add_comment(node.comment)
        yield data
        data.extend(self.construct_rt_sequence(node, data))
        self.set_collection_style(data, node)

    def construct_yaml_map(self, node: Any) -> Iterator[CommentedMap]:
        data = CommentedMap()
        data._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
        yield data
        self.construct_mapping(node, data, deep=True)
        self.set_collection_style(data, node)

    def set_collection_style(self, data: Any, node: Any) -> None:
        if len(data) == 0:
            return
        if node.flow_style is True:
            data.fa.set_flow_style()
        elif node.flow_style is False:
            data.fa.set_block_style()

    def construct_yaml_object(self, node: Any, cls: Any) -> Any:
        from dataclasses import is_dataclass, InitVar, MISSING

        data = cls.__new__(cls)
        yield data
        if hasattr(data, '__setstate__'):
            state = SafeConstructor.construct_mapping(self, node, deep=True)
            data.__setstate__(state)
        elif is_dataclass(data):
            mapping = SafeConstructor.construct_mapping(self, node)
            init_var_defaults = {}
            for field in data.__dataclass_fields__.values():
                # nprintf('field', field, field.default is MISSING,
                #          isinstance(field.type, InitVar))
                # in 3.7, InitVar is a singleton
                if (
                    isinstance(field.type, InitVar) or field.type is InitVar
                ) and field.default is not MISSING:
                    init_var_defaults[field.name] = field.default
            for attr, value in mapping.items():
                if attr not in init_var_defaults:
                    setattr(data, attr, value)
            post_init = getattr(data, '__post_init__', None)
            if post_init is not None:
                kw = {}
                for name, default in init_var_defaults.items():
                    kw[name] = mapping.get(name, default)
                post_init(**kw)
        else:
            state = SafeConstructor.construct_mapping(self, node)
            if hasattr(data, '__attrs_attrs__'):  # issue 394
                data.__init__(**state)
            else:
                data.__dict__.update(state)
        if node.anchor:
            from ...._vendor.ruamel.yaml.serializer import templated_id
            from ...._vendor.ruamel.yaml.anchor import Anchor

            if not templated_id(node.anchor):
                if not hasattr(data, Anchor.attrib):
                    a = Anchor()
                    setattr(data, Anchor.attrib, a)
                else:
                    a = getattr(data, Anchor.attrib)
                a.value = node.anchor

    def construct_yaml_omap(self, node: Any) -> Iterator[CommentedOrderedMap]:
        # Note: we do now check for duplicate keys
        omap = CommentedOrderedMap()
        omap._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
        if node.flow_style is True:
            omap.fa.set_flow_style()
        elif node.flow_style is False:
            omap.fa.set_block_style()
        yield omap
        if self.loader and self.loader.comment_handling is None:
            if node.comment:
                omap._yaml_add_comment(node.comment[:2])
                if len(node.comment) > 2:
                    omap.yaml_end_comment_extend(node.comment[2], clear=True)
        else:
            # NEWCMNT
            if node.comment:
                nprintf('nc8', node.comment)
        if not isinstance(node, SequenceNode):
            raise ConstructorError(
                'while constructing an ordered map',
                node.start_mark,
                f'expected a sequence, but found {node.id!s}',
                node.start_mark,
            )
        for subnode in node.value:
            if not isinstance(subnode, MappingNode):
                raise ConstructorError(
                    'while constructing an ordered map',
                    node.start_mark,
                    f'expected a mapping of length 1, but found {subnode.id!s}',
                    subnode.start_mark,
                )
            if len(subnode.value) != 1:
                raise ConstructorError(
                    'while constructing an ordered map',
                    node.start_mark,
                    f'expected a single mapping item, but found {len(subnode.value):d} items',
                    subnode.start_mark,
                )
            key_node, value_node = subnode.value[0]
            key = self.construct_object(key_node)
            assert key not in omap
            value = self.construct_object(value_node)
            if self.loader and self.loader.comment_handling is None:
                if key_node.comment:
                    omap._yaml_add_comment(key_node.comment, key=key)
                if subnode.comment:
                    omap._yaml_add_comment(subnode.comment, key=key)
                if value_node.comment:
                    omap._yaml_add_comment(value_node.comment, value=key)
            else:
                # NEWCMNT
                if key_node.comment:
                    nprintf('nc9a', key_node.comment)
                if subnode.comment:
                    nprintf('nc9b', subnode.comment)
                if value_node.comment:
                    nprintf('nc9c', value_node.comment)
            omap[key] = value

    def construct_yaml_set(self, node: Any) -> Iterator[CommentedSet]:
        data = CommentedSet()
        data._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
        if node.flow_style is True:
            data.fa.set_flow_style()
        elif node.flow_style is False:
            data.fa.set_block_style()
        yield data
        self.construct_setting(node, data)

    def construct_unknown(
        self, node: Any,
    ) -> Iterator[Union[CommentedMap, TaggedScalar, CommentedSeq]]:
        try:
            if isinstance(node, MappingNode):
                data = CommentedMap()
                data._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
                if node.flow_style is True:
                    data.fa.set_flow_style()
                elif node.flow_style is False:
                    data.fa.set_block_style()
                data.yaml_set_ctag(node.ctag)
                yield data
                if node.anchor:
                    from ...._vendor.ruamel.yaml.serializer import templated_id

                    if not templated_id(node.anchor):
                        data.yaml_set_anchor(node.anchor)
                self.construct_mapping(node, data)
                return
            elif isinstance(node, ScalarNode):
                data2 = TaggedScalar()
                data2.value = self.construct_scalar(node)
                data2.style = node.style
                data2.yaml_set_ctag(node.ctag)
                yield data2
                if node.anchor:
                    from ...._vendor.ruamel.yaml.serializer import templated_id

                    if not templated_id(node.anchor):
                        data2.yaml_set_anchor(node.anchor, always_dump=True)
                return
            elif isinstance(node, SequenceNode):
                data3 = CommentedSeq()
                data3._yaml_set_line_col(node.start_mark.line, node.start_mark.column)
                if node.flow_style is True:
                    data3.fa.set_flow_style()
                elif node.flow_style is False:
                    data3.fa.set_block_style()
                data3.yaml_set_ctag(node.ctag)
                yield data3
                if node.anchor:
                    from ...._vendor.ruamel.yaml.serializer import templated_id

                    if not templated_id(node.anchor):
                        data3.yaml_set_anchor(node.anchor)
                data3.extend(self.construct_sequence(node))
                return
        except:  # NOQA
            pass
        raise ConstructorError(
            None,
            None,
            f'could not determine a constructor for the tag {node.tag!r}',
            node.start_mark,
        )

    def construct_yaml_timestamp(
        self, node: Any, values: Any = None,
    ) -> Union[datetime.date, datetime.datetime, TimeStamp]:
        try:
            match = self.timestamp_regexp.match(node.value)
        except TypeError:
            match = None
        if match is None:
            raise ConstructorError(
                None,
                None,
                f'failed to construct timestamp from "{node.value}"',
                node.start_mark,
            )
        values = match.groupdict()
        if not values['hour']:
            return create_timestamp(**values)
            # return SafeConstructor.construct_yaml_timestamp(self, node, values)
        for part in ['t', 'tz_sign', 'tz_hour', 'tz_minute']:
            if values[part]:
                break
        else:
            return create_timestamp(**values)
            # return SafeConstructor.construct_yaml_timestamp(self, node, values)
        dd = create_timestamp(**values)  # this has delta applied
        delta = None
        if values['tz_sign']:
            tz_hour = int(values['tz_hour'])
            minutes = values['tz_minute']
            tz_minute = int(minutes) if minutes else 0
            delta = datetime.timedelta(hours=tz_hour, minutes=tz_minute)
            if values['tz_sign'] == '-':
                delta = -delta
        # should check for None and solve issue 366 should be tzinfo=delta)
        # isinstance(datetime.datetime.now, datetime.date) is true)
        if isinstance(dd, datetime.datetime):
            data = TimeStamp(
                dd.year, dd.month, dd.day, dd.hour, dd.minute, dd.second, dd.microsecond,
            )
        else:
            # ToDo: make this into a DateStamp?
            data = TimeStamp(dd.year, dd.month, dd.day, 0, 0, 0, 0)
            return data
        if delta:
            data._yaml['delta'] = delta
            tz = values['tz_sign'] + values['tz_hour']
            if values['tz_minute']:
                tz += ':' + values['tz_minute']
            data._yaml['tz'] = tz
        else:
            if values['tz']:  # no delta
                data._yaml['tz'] = values['tz']
        if values['t']:
            data._yaml['t'] = True
        return data

    def construct_yaml_sbool(self, node: Any) -> Union[bool, ScalarBoolean]:
        b = SafeConstructor.construct_yaml_bool(self, node)
        if node.anchor:
            return ScalarBoolean(b, anchor=node.anchor)
        return b


RoundTripConstructor.add_default_constructor('bool', method='construct_yaml_sbool')

for tag in 'null int float binary timestamp omap pairs set str seq map'.split():
    RoundTripConstructor.add_default_constructor(tag)

RoundTripConstructor.add_constructor(None, RoundTripConstructor.construct_unknown)