fix bug with generic

openbb_sdk/sdk/core/openbb_core/app/provider_interface.py

@@ -416,7 +416,7 @@ class ProviderInterface:
                     types_list.append(ret)
 
             if types_list:
-                returns[model_name] = Union[*types_list]  # type: ignore
+                returns[model_name] = Union[tuple(types_list)]  # type: ignore
 
         return returns
 
@@ -455,7 +455,8 @@ class ProviderInterface:
             )
 
             ReturnType = merged_return_type.get(model_name, GenericDataType)
-            result[model_name] = ReturnType[ReturnModel]  # type: ignore
+            n_params = len(getattr(ReturnType, "__parameters__", ()))
+            result[model_name] = ReturnType[tuple([ReturnModel] * n_params)]  # type: ignore
 
         return result
 

openbb_sdk/sdk/provider/openbb_provider/abstract/fetcher.py

@@ -1,6 +1,7 @@
 """Abstract class for the fetcher."""
 
 
+from abc import abstractmethod
 from typing import Any, Dict, Generic, List, Optional, TypeVar, Union
 
 from openbb_provider.abstract.data import Data
@@ -77,6 +78,8 @@ class Fetcher(
         # pylint: disable=E1101
         return self.__orig_bases__[0].__args__[3]
 
-    # TODO: Create abstract class attribute for generic return type
     # @property
+    # @abstractmethod
     # def generic_return_type(self):
+    #     """Get the type of the generic return."""
+    #     raise NotImplementedError