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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 gather(self):
 """Return all the messages represented by this object. This will always be a list of a single message. :rtype: list[~uamqp.message.Message] """

        if self.state in constants.RECEIVE_STATES:
            raise TypeError("Only new messages can be gathered.")
        if not self._message:
            raise ValueError("Message data already consumed.")
        try:
            raise self._response
        except TypeError:
            pass
        return [self]