'Fail the L{Deferred} for the current request, notify the request
object that it does not need to continue transmitting itself, and
move to the C{\'CONNECTION_LOST\'} state.'

def _connectionLost_TRANSMITTING(self, reason):

    self._state = 'CONNECTION_LOST'
    self._finishedRequest.errback(Failure(RequestTransmissionFailed([reason])))
    del self._finishedRequest
    self._currentRequest.stopWriting()
