comparison_in_list : IN
                           | NOT IN

def p_comparison_in_list(self, p):
        """
        comparison_in_list : IN
                           | NOT IN
        """
        if len(p) == 2:
            p[0] = Comparison(operator=p[1])
        else:
            p[0] = Comparison(operator='%s %s' % (p[1], p[2]))