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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 _get_arg_spec(func):
 """ Gets the argument spec of the given function, returning defaults as a dict of param names to values """

        args, varargs, keywords, defaults = inspect.getargspec(func)

        # build a mapping from argument names to their default values, if any:
        if defaults is None:
            defaults = {}
        else:
            defaulted_args = args[-len(defaults):]
            defaults = {name: val for name, val in zip(defaulted_args, defaults)}

        return args, varargs, defaults