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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_var(self, tokens, item):
 """Matches a variable."""

        setvar, = tokens
        if setvar != wildcard:
            if setvar in self.names:
                self.add_check(self.names[setvar] + " == " + item)
            else:
                self.add_def(setvar + " = " + item)
                self.names[setvar] = item