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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 macro2blackbox_outputs(self, macro_indices):
 """Given a set of macro elements, return the blackbox output elements which compose these elements. """

        if not self.blackbox:
            raise ValueError('System is not blackboxed')

        return tuple(sorted(set(
            self.macro2micro(macro_indices)
        ).intersection(self.blackbox.output_indices)))