A negated query is one in which every clause has a presence of
        prohibited. These queries require some special processing to return
        the expected results.

def is_negated(self):
        """A negated query is one in which every clause has a presence of
        prohibited. These queries require some special processing to return
        the expected results.
        """
        return all(
            clause.presence == QueryPresence.PROHIBITED for clause in self.clauses
        )