@Test
    public void testLeftOuterSelfJoin() {
        BiPredicate<Object, Object> TRUE = (t, u) -> true;

        assertEquals(asList(),
            Seq.of().leftOuterSelfJoin(TRUE).toList());

        assertEquals(asList(
            tuple(tuple(1, 0), (Tuple2<Integer, Integer>) null),
            tuple(tuple(2, 1), tuple(1,0))),
            Seq.of(tuple(1, 0), tuple(2, 1)).leftOuterSelfJoin((t, u) -> t.v2 == u.v1).toList());
    }
@author Lukas Eder
@author Roman Tkalenko
jOOL/src/test/java/org/jooq/lambda/SeqTest.java