def lifecycle_initial_value(self, field_name: str) -> typing.Any:
        """
        Get initial value of field when model was instantiated.
        """
        field_name = self._sanitize_field_name(field_name)

        if field_name in self._initial_state:
            return self._initial_state[field_name]

        return None

        Get initial value of field when model was instantiated.
        
api/features/custom_lifecycle.py