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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 Expression(*args, **kwargs):
 """ Return an appropriate Expression given the arguments Parameters args : tuple Positional arguments passed to the Expression class kwargs : dict Keyword arguments passed to the Expression class """

    # dispatch
    if not hasattr(args[0], '_Expression'):
        return BaseExpression(*args, *kwargs)
    else:
        return args[0]._Expression(*args, **kwargs)