def issuperset(self, other):
        """Is I{self} a superset of I{other}?

        @rtype: bool
        """

        if not isinstance(other, Set):
            raise ValueError('other must be a Set instance')
        for item in other.items:
            if not item in self.items:
                return False
        return True
Is I{self} a superset of I{other}?

        @rtype: bool