'Deliver the accumulated response bytes to the waiting L{Deferred}, if
the response body has been completely received without error.'

def connectionLost(self, reason):

    if reason.check(ResponseDone):
        self.deferred.callback(''.join(self.dataBuffer))
    elif reason.check(PotentialDataLoss):
        self.deferred.errback(PartialDownloadError(self.status, self.message, ''.join(self.dataBuffer)))
    else:
        self.deferred.errback(reason)
