'L{PosixReactorBase._removeAll} returns a list of removed
L{IReadDescriptor} and L{IWriteDescriptor} objects.'

def test_removeAllReturnsRemovedDescriptors(self):

    reactor = TrivialReactor()
    reader = object()
    writer = object()
    reactor.addReader(reader)
    reactor.addWriter(writer)
    removed = reactor._removeAll(reactor._readers, reactor._writers)
    self.assertEqual(set(removed), set([reader, writer]))
    self.assertNotIn(reader, reactor._readers)
    self.assertNotIn(writer, reactor._writers)
