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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)