@Test
void before() {

    assertThat(Range.of(10L, 20L).before(9)).isFalse();
    assertThat(Range.of(10L, 20L).before(10)).isFalse();
    assertThat(Range.of(10L, 20L).before(15)).isFalse();
    assertThat(Range.of(10L, 20L).before(19)).isFalse();
    assertThat(Range.of(10L, 20L).before(20L)).isTrue();
}