code: def get_object_header(self, ref):
  		
  		cmd = self.__get_persistent_cmd("cat_file_header", "cat_file", batch_check=True)
  		return self.__get_object_header(cmd, ref)
docs: 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)