Add future import

Author: DavidMStraub

gedcom7/cast.py

@@ -1,9 +1,11 @@
 """Cast strings values to the appropriate data type."""
 
+from __future__ import annotations
+
 import re
 from collections.abc import Callable
 
-from . import const, types, grammar
+from . import const, grammar, types
 
 
 def cast_value(text: str, type_id: str) -> types.DataType | None:

gedcom7/types.py

@@ -1,9 +1,11 @@
 """Classes and data types."""
 
+from __future__ import annotations
+
+from dataclasses import dataclass, field
 from typing import Literal, Union
 
 from . import const
-from dataclasses import dataclass, field
 
 
 @dataclass