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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 str(self,local):
 """ Return the string representation of the time range :param local: if False [default] use UTC datetime. If True use localtz """

        s = self.start_time.str(local) \
            + u" to " \
            + self.end_time.str(local)
        return s