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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 _combine(self, original, loc, tokens):
 """Implement the parse action for Combine."""

        combined_tokens = super(CombineNode, self).postParse(original, loc, tokens)
        internal_assert(len(combined_tokens) == 1, "Combine produced multiple tokens", combined_tokens)
        return combined_tokens[0]