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Complete this python program:
def deferred(timeout=None):
assistant
#Here is the Python code you requested.

    """By wrapping a test function with this decorator, you can return a
    twisted Deferred and the test will wait for the deferred to be triggered.
    The whole test function will run inside the Twisted event loop.
    The optional timeout parameter specifies the maximum duration of the test.
    The difference with timed() is that timed() will still wait for the test
    to end, while deferred() will stop the test when its timeout has expired.
    The latter is more desireable when dealing with network tests, because
    the result may actually never arrive.
    If the callback is triggered, the test has passed.
    If the errback is triggered or the timeout expires, the test has failed.
    Example::
    @deferred(timeout=5.0)
    def test_resolve():
    return reactor.resolve("www.python.org")
    Attention! If you combine this decorator with other decorators (like
    "raises"), deferred() must be called *first*!
    In other words, this is good::
    @raises(DNSLookupError)
    @deferred()
    def test_error():
    return reactor.resolve("xxxjhjhj.biz")
    and this is bad::
    @deferred()
    @raises(DNSLookupError)
    def test_error():
    return reactor.resolve("xxxjhjhj.biz")
    """
    (reactor, reactor_thread) = threaded_reactor()
    if (reactor is None):
        raise ImportError('twisted    is    not    available    or    could    not    be    imported')
    try:
        ((timeout is None) or (timeout + 0))
    except TypeError:
        raise TypeError("'timeout'    argument    must    be    a    number    or    None")
    def decorate(func):
        def wrapper(*args, **kargs):
            q = Queue()
            def callback(value):
                q.put(None)
            def errback(failure):
                try:
                    failure.raiseException()
                except:
                    q.put(sys.exc_info())
            def g():
                try:
                    d = func(*args, **kargs)
                    try:
                        d.addCallbacks(callback, errback)
                    except AttributeError:
                        raise TypeError('you    must    return    a    twisted    Deferred    from    your    test    case!')
                except:
                    q.put(sys.exc_info())
            reactor.callFromThread(g)
            try:
                error = q.get(timeout=timeout)
            except Empty:
                raise TimeExpired(('timeout    expired    before    end    of    test    (%f    s.)' % timeout))
            if (error is not None):
                (exc_type, exc_value, tb) = error
                raise exc_type, exc_value, tb
        wrapper = make_decorator(func)(wrapper)
        return wrapper
    return decorate