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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 AddArg(self, argument):
 """Adds a new argument to this expression. Args: argument (str):
 argument to add. Returns: True if the argument is the last argument, False otherwise. Raises: ParseError: If there are too many arguments. """

    self.args.append(argument)
    if len(self.args) > self.number_of_args:
      raise errors.ParseError('Too many arguments for this expression.')

    elif len(self.args) == self.number_of_args:
      return True

    return False