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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 visit_parenthesized(self, node, parenthesized):
 """Treat a parenthesized subexpression as just its contents. Its position in the tree suffices to maintain its grouping semantics. """

        left_paren, _, expression, right_paren, _ = parenthesized
        return expression