Executable model isn't generated correctly for from clause in the form func(x)

    public static Integer getLength(String s) {
        return s.length();
    }

    @Test
    public void testFromExternalFunction() {
        final String str =
                "import " + FromTest.class.getCanonicalName() + ";\n" +
                "global java.util.List list\n" +
                "\n" +
                "rule R when\n" +
                "  $s : String()\n" +
                "  $i : Integer( this > 10 ) from FromTest.getLength($s)\n" +
                "then\n" +
                "  list.add( \"received long message: \" + $s);\n" +
                "end\n";

        KieSession ksession = getKieSession( str );

        final List<String> list = new ArrayList<>();
        ksession.setGlobal( "list", list );

        ksession.insert("Hello World!");
        ksession.fireAllRules();

        Assertions.assertThat(list).containsExactlyInAnyOrder("received long message: Hello World!");
    }