'Handle the expiration of the timeout for the child process to exit by
terminating the child process forcefully and issuing a failure to the
L{completion} deferred.'

def _completionCancel(self):

    self._timeoutCallID = None
    self.protocol.transport.signalProcess('KILL')
    exc = ProcessAliasTimeout(('No    answer    after    %s    seconds' % (self.completionTimeout,)))
    self.protocol.onEnd = None
    self.completion.errback(failure.Failure(exc))
