Fixes circular dependencies

Signed-off-by: Christopher Grote <cmgrote@users.noreply.github.com>

Author: cmgrote

pyatlan/client/atlan.py

@@ -77,7 +77,6 @@
     TypeDefResponse,
 )
 from pyatlan.utils import HTTPStatus, get_logger
-from pyatlan.cache import CustomMetadataCache, ClassificationCache
 
 LOGGER = get_logger()
 T = TypeVar("T", bound=Referenceable)
@@ -484,15 +483,19 @@ def create_typedef(self, typedef: TypeDef) -> TypeDefResponse:
             CREATE_TYPE_DEFS, request_obj=payload, exclude_unset=False
         )
         if isinstance(typedef, ClassificationDef):
+            from pyatlan.cache.classification_cache import ClassificationCache
             ClassificationCache.refresh_cache()
         if isinstance(typedef, CustomMetadataDef):
+            from pyatlan.cache.custom_metadata_cache import CustomMetadataCache
             CustomMetadataCache.refresh_cache()
         return TypeDefResponse(**raw_json)
 
     def purge_typedef(self, internal_name: str) -> None:
         self._call_api(DELETE_TYPE_DEF_BY_NAME.format_path_with_params(internal_name))
         # TODO: if we know which kind of typedef is being purged, we only need
         #  to refresh that particular cache
+        from pyatlan.cache.classification_cache import ClassificationCache
+        from pyatlan.cache.custom_metadata_cache import CustomMetadataCache
         ClassificationCache.refresh_cache()
         CustomMetadataCache.refresh_cache()