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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 intersection(self, key, *others):
 """Return a new set with elements common to the set and all others."""

        if not isinstance(key, str):
            raise ValueError("String expected.")
        self.db.sinterstore(key, [self.key] + [o.key for o in others])
        return Set(key)