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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 connectionLost(self, reason):
 """ Called when the body is complete or the connection was lost. @note: As the body length is usually not known at the beginning of the response we expect a L{PotentialDataLoss} when Twitter closes the stream, instead of L{ResponseDone}. Other exceptions are treated as error conditions. """

        self.setTimeout(None)
        if reason.check(ResponseDone, PotentialDataLoss):
            self.deferred.callback(None)
        else:
            self.deferred.errback(reason)