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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 default(cls):
 """ Get the first available event loop implementation based on which packages are installed. """

        with enamlnative.imports():
            for impl in [
                TornadoEventLoop,
                TwistedEventLoop,
                BuiltinEventLoop,
            ]:
                if impl.available():
                    print("Using {} event loop!".format(impl))
                    return impl()
        raise RuntimeError("No event loop implementation is available. "
                           "Install tornado or twisted.")