def METHOD_NAME(self):
    """
    Removing a filesystem file writer from a reactor will make sure it is
    no longer polled.
    """
    reactor = self.buildReactor()
    self.addCleanup(self.unbuildReactor, reactor)
    # Cleanup might fail if file is GCed too soon:
    self.f = f = open(self.mktemp(), "wb")
    # Have the reader added:
    protocol = Protocol()
    stdio = StandardIO(
        protocol, stdout=f.fileno(), stdin=self.extraFile.fileno(), reactor=reactor
    )
    protocol.transport.write(b"hello")
    self.assertIn(stdio._writer, reactor.getWriters())
    stdio._writer.stopWriting()
    self.assertNotIn(stdio._writer, reactor.getWriters())