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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 at(self, hour, minute=0, second=0, microsecond=0):
 """ Returns a new instance with the current time to a different time. :param hour: The hour :type hour: int :param minute: The minute :type minute: int :param second: The second :type second: int :param microsecond: The microsecond :type microsecond: int :rtype: DateTime """

        return self.set(
            hour=hour, minute=minute, second=second, microsecond=microsecond
        )