typo

Author: Leon Huang

sdk/basyx/aas/model/submodel.py

@@ -1120,7 +1120,7 @@ def __init__(self,
         self._validate_aasd_014(entity_type, global_asset_id, bool(specific_asset_id))
 
     @property
-    def entity_type(self) -> base.EntityType | None:
+    def entity_type(self) -> Optional[base.EntityType]:
         return self._entity_type
 
     @entity_type.setter
@@ -1171,7 +1171,7 @@ def _validate_aasd_014(entity_type: Optional[base.EntityType],
                            global_asset_id: Optional[base.Identifier],
                            specific_asset_id_nonempty: bool) -> None:
         if entity_type is None:
-            return 
+            return
         if entity_type == base.EntityType.SELF_MANAGED_ENTITY and global_asset_id is None \
                 and not specific_asset_id_nonempty:
             raise base.AASConstraintViolation(