@Test
    public void testGet() {
        assertEquals(Optional.empty(), Seq.of(1, 2, 3).get(-1));
        assertEquals(Optional.of(1), Seq.of(1, 2, 3).get(0));
        assertEquals(Optional.of(2), Seq.of(1, 2, 3).get(1));
        assertEquals(Optional.of(3), Seq.of(1, 2, 3).get(2));
        assertEquals(Optional.empty(), Seq.of(1, 2, 3).get(3));
    }
@author Lukas Eder
@author Roman Tkalenko
jOOL-java-8/src/test/java/org/jooq/lambda/SeqTest.java