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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 _startup(rootFuture, *args, **kargs):
 """Initializes the SCOOP environment. :param rootFuture: Any callable object (function or class object with *__call__* method); this object will be called once and allows the use of parallel calls inside this object. :param args: A tuple of positional arguments that will be passed to the callable object. :param kargs: A dictionary of additional keyword arguments that will be passed to the callable object. :returns: The result of the root Future. Be sure to launch your root Future using this method."""

    import greenlet
    global _controller
    _controller = greenlet.greenlet(control.runController)
    try:
        result = _controller.switch(rootFuture, *args, **kargs)
    except scoop._comm.Shutdown:
        result = None
        control.execQueue.shutdown()
    return result