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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 multi_flags_validator(flag_names, message='Flag validation failed', flag_values=FLAGS):
 """A function decorator for defining a multi-flag validator. Registers the decorated function as a validator for flag_names, e.g. @gflags.multi_flags_validator(['foo', 'bar']) def _CheckFooBar(flags_dict):
 See register_multi_flags_validator() for the specification of checker function. Args: flag_names: [str], a list of the flag names to be checked. message: error text to be shown to the user if checker returns False. If checker raises ValidationError, message from the raised error will be shown. flag_values: An optional FlagValues instance to validate against. Returns: A function decorator that registers its function argument as a validator. Raises: AttributeError: If a flag is not registered as a valid flag name. """


  def decorate(function):
    register_multi_flags_validator(flag_names,
                                   function,
                                   message=message,
                                   flag_values=flag_values)
    return function

  return decorate