Helper function for schema_from_json that takes a
       file object that describes a table schema.

       Returns:
            List of schema field objects.

def _schema_from_json_file_object(self, file_obj):
        """Helper function for schema_from_json that takes a
       file object that describes a table schema.

       Returns:
            List of schema field objects.
        """
        json_data = json.load(file_obj)
        return [SchemaField.from_api_repr(field) for field in json_data]