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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 delete_value(self, key):
 """ Delete the key if the token is expired. Arg: key : cache key """

        response = {}
        response['status'] = False
        response['msg'] = "key does not exist"

        file_cache = self.read_file()
        if key in file_cache:
            del file_cache[key]
            self.update_file(file_cache)
            response['status'] = True
            response['msg'] = "success"
        return response