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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def fork(executable, args=(), env={}, path=None, timeout=3600):
 """fork Provides a deferred wrapper function with a timeout function :param executable: Executable :type executable: str. :param args: Tupple of arguments :type args: tupple. :param env: Environment dictionary :type env: dict. :param timeout: Kill the child process if timeout is exceeded :type timeout: int. """

    d = defer.Deferred()
    p = ProcessProtocol(d, timeout)
    reactor.spawnProcess(p, executable, (executable,)+tuple(args), env, path)
    return d