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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 is_a_Builder(obj):
 """"Returns True if the specified obj is one of our Builder classes. The test is complicated a bit by the fact that CompositeBuilder is a proxy, not a subclass of BuilderBase. """

    return (isinstance(obj, BuilderBase)
            or isinstance(obj, CompositeBuilder)
            or callable(obj))