TypeAliasType.__type_params__ can return forms from typing_extensions

Author: carljm

stdlib/typing.pyi

@@ -1133,6 +1133,15 @@ if sys.version_info >= (3, 10):
 def _type_repr(obj: object) -> str: ...
 
 if sys.version_info >= (3, 12):
+    _TypeVariable: TypeAlias = (
+        TypeVar
+        | typing_extensions.TypeVar
+        | ParamSpec
+        | typing_extensions.ParamSpec
+        | TypeVarTuple
+        | typing_extensions.TypeVarTuple
+    )
+
     def override(method: _F, /) -> _F: ...
     @final
     class TypeAliasType:
@@ -1141,20 +1150,12 @@ if sys.version_info >= (3, 12):
             name: str,
             value: Any,
             *,
-            type_params: tuple[
-                TypeVar
-                | typing_extensions.TypeVar
-                | ParamSpec
-                | typing_extensions.ParamSpec
-                | TypeVarTuple
-                | typing_extensions.TypeVarTuple,
-                ...,
-            ] = (),
+            type_params: tuple[_TypeVariable, ...] = (),
         ) -> Self: ...
         @property
         def __value__(self) -> Any: ...  # AnnotationForm
         @property
-        def __type_params__(self) -> tuple[TypeVar | ParamSpec | TypeVarTuple, ...]: ...
+        def __type_params__(self) -> tuple[_TypeVariable, ...]: ...
         @property
         def __parameters__(self) -> tuple[Any, ...]: ...  # AnnotationForm
         @property