Get the set of names owned by a particular address.
        NOTE: only works for cases where we could extract an address.

def get_names_owned_by_address( self, address ):
        """
        Get the set of names owned by a particular address.
        NOTE: only works for cases where we could extract an address.
        """
        cur = self.db.cursor()
        names = namedb_get_names_owned_by_address( cur, address, self.lastblock )
        return names