@Test
    public void testNotExists() {

        String drl2 =
                "import " + List.class.getCanonicalName() + ";\n"
                + "\n\n"
                + "rule \"NotExists\"\n"
                + "when\n"
                + "$l1: List() \n"
                + "$l2: List() \n"
                + "exists( String() from $l1 ) \n"
                + "not( exists( String() ) )\n"
                + "then end\n";

        KieSession ksession = new KieHelper().addContent(drl2, ResourceType.DRL)
                                             .build()
                                             .newKieSession();

        ksession.insert(asList("Mario", "Mark"));
        ksession.insert(asList("Julie", "Leiti"));

        assertEquals(4, ksession.fireAllRules());
    }