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)

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)