@Test
    public void testIsEmpty() {
        assertTrue(Seq.empty().isEmpty());
        assertFalse(Seq.empty().isNotEmpty());

        assertFalse(Seq.of(1).isEmpty());
        assertFalse(Seq.of(1, 2).isEmpty());
        assertTrue(Seq.of(1).isNotEmpty());
        assertTrue(Seq.of(1, 2).isNotEmpty());
    }
@author Lukas Eder
@author Roman Tkalenko
jOOL/src/test/java/org/jooq/lambda/SeqTest.java