Fix tests

Author: Natim

tests/test_models.py

@@ -9,7 +9,7 @@
 
 from openai._utils import PropertyInfo
 from openai._compat import PYDANTIC_V1, parse_obj, model_dump, model_json
-from openai._models import BaseModel, construct_type
+from openai._models import BaseModel, construct_type, _DISCRIMINATOR_CACHE
 
 
 class BasicModel(BaseModel):
@@ -809,7 +809,7 @@ class B(BaseModel):
 
     UnionType = cast(Any, Union[A, B])
 
-    assert not hasattr(UnionType, "__discriminator__")
+    assert _DISCRIMINATOR_CACHE.get(UnionType) is None
 
     m = construct_type(
         value={"type": "b", "data": "foo"}, type_=cast(Any, Annotated[UnionType, PropertyInfo(discriminator="type")])
@@ -818,7 +818,8 @@ class B(BaseModel):
     assert m.type == "b"
     assert m.data == "foo"  # type: ignore[comparison-overlap]
 
-    discriminator = UnionType.__discriminator__
+    discriminator = _DISCRIMINATOR_CACHE.get(UnionType)
+
     assert discriminator is not None
 
     m = construct_type(
@@ -830,7 +831,7 @@ class B(BaseModel):
 
     # if the discriminator details object stays the same between invocations then
     # we hit the cache
-    assert UnionType.__discriminator__ is discriminator
+    assert _DISCRIMINATOR_CACHE.get(UnionType) is discriminator
 
 
 @pytest.mark.skipif(PYDANTIC_V1, reason="TypeAliasType is not supported in Pydantic v1")