'If there is still a parser, call its C{connectionLost} method with the
given reason.  If there is not, do nothing.
@type reason: L{Failure}'

def _disconnectParser(self, reason):

    if (self._parser is not None):
        parser = self._parser
        self._parser = None
        self._currentRequest = None
        self._finishedRequest = None
        self._responseDeferred = None
        self._transportProxy._stopProxying()
        self._transportProxy = None
        parser.connectionLost(reason)
