'Any L{IReadDescriptors} in L{PosixReactorBase._internalReaders} are
left alone by L{PosixReactorBase._removeAll}.'

def test_removeAllSkipsInternalReaders(self):

    reactor = TrivialReactor()
    extra = object()
    reactor._internalReaders.add(extra)
    reactor.addReader(extra)
    reactor._removeAll(reactor._readers, reactor._writers)
    self._checkWaker(reactor)
    self.assertIn(extra, reactor._internalReaders)
    self.assertIn(extra, reactor._readers)
