'Helper for getReaders and getWriters tests.'

def _getFDTest(self, kind):

    reactor = self.buildReactor()
    get = getattr(reactor, (('get' + kind) + 's'))
    add = getattr(reactor, ('add' + kind))
    remove = getattr(reactor, ('remove' + kind))
    (client, server) = self._connectedPair()
    self.assertNotIn(client, get())
    self.assertNotIn(server, get())
    add(client)
    self.assertIn(client, get())
    self.assertNotIn(server, get())
    remove(client)
    self.assertNotIn(client, get())
    self.assertNotIn(server, get())
