def get_object_header(self, ref):
        """ Use this method to quickly examine the type and size of the object behind
        the given ref.

        :note: The method will only suffer from the costs of command invocation
            once and reuses the command in subsequent calls.

        :return: (hexsha, type_string, size_as_int)"""
        cmd = self._get_persistent_cmd("cat_file_header", "cat_file", batch_check=True)
        return self.__get_object_header(cmd, ref)
Use this method to quickly examine the type and size of the object behind
        the given ref.

        :note: The method will only suffer from the costs of command invocation
            once and reuses the command in subsequent calls.

        :return: (hexsha, type_string, size_as_int)