Add multi configuration section support (hyperparams and configurations)

Support setting offline mode API version using TRAINS_OFFLINE_MODE env var

trains/backend_api/session/datamodel.py

@@ -64,7 +64,11 @@ class DataModel(object):
 
     @classmethod
     def _to_base_type(cls, value):
-        if isinstance(value, DataModel):
+        if isinstance(value, dict):
+            # Note: this should come before DataModel to handle data models that are simply a dict
+            # (and thus are not expected to have additional named properties)
+            return {k: cls._to_base_type(v) for k, v in value.items()}
+        elif isinstance(value, DataModel):
             return value.to_dict()
         elif isinstance(value, enum.Enum):
             return value.value

trains/backend_api/session/session.py

@@ -62,6 +62,7 @@ class Session(TokenManager):
     default_files = "https://demofiles.trains.allegro.ai"
     default_key = "EGRTCO8JMSIGI6S39GTP43NFWXDQOW"
     default_secret = "x!XTov_G-#vspE*Y(h$Anm&DIc5Ou-F)jsl$PdOyj5wG1&E!Z8"
+    force_max_api_version = None
 
     # TODO: add requests.codes.gateway_timeout once we support async commits
     _retry_codes = [
@@ -182,6 +183,9 @@ class Session(TokenManager):
 
         self.__class__._sessions_created += 1
 
+        if self.force_max_api_version and self.check_min_api_version(self.force_max_api_version):
+            Session.api_version = str(self.force_max_api_version)
+
     def _send_request(
         self,
         service,
@@ -539,7 +543,17 @@ class Session(TokenManager):
         # If no session was created, create a default one, in order to get the backend api version.
         if cls._sessions_created <= 0:
             if cls._offline_mode:
-                cls.api_version = cls._offline_default_version
+                # allow to change the offline mode version by setting ENV_OFFLINE_MODE to the required API version
+                if cls.api_version != cls._offline_default_version:
+                    offline_api = ENV_OFFLINE_MODE.get(converter=lambda x: x)
+                    if offline_api:
+                        try:
+                            # check cast to float, but leave original str if we pass it.
+                            float(offline_api)
+                            cls._offline_default_version = str(offline_api)
+                        except ValueError:
+                            pass
+                    cls.api_version = cls._offline_default_version
             else:
                 # noinspection PyBroadException
                 try: