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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 match_set(self, tokens, item):
 """Matches a set."""

        match, = tokens
        self.add_check("_coconut.isinstance(" + item + ", _coconut.abc.Set)")
        self.add_check("_coconut.len(" + item + ") == " + str(len(match)))
        for const in match:
            self.add_check(const + " in " + item)