@Test
public void testReplaceAll() {

    DoubleList list = new DoubleList();
    list.replaceAll(o -> o + 1);
    assertThat(list.toArray()).isEmpty();
    list.add(1d);
    list.add(2d);
    list.replaceAll(o -> o + 1);
    assertThat(list.toArray()).containsExactly(2d, 3d);
}