@Test
    public void testGroupedOnEmptySeq() throws Exception {
        Seq<int[]> seq = Seq.empty();
        assertEquals(Seq.empty().toList(), seq.grouped(xs -> xs.length).toList());
    }
@author Lukas Eder
@author Roman Tkalenko
jOOL-java-8/src/test/java/org/jooq/lambda/SeqTest.java