@Test
public void shouldAddNewNodeValueToLeavesWhenAddingToLastNodeInIndexTree() {

    // given
    LevelIndex<Integer> levelIndex = levelIndex().withLevelCount(0).build();
    LevelNode<Integer> node = new LevelNode<Integer>(levelIndex);
    // when
    int currentLevelNumber = 0;
    node.add(new String[]{}, 10, currentLevelNumber);
    // then
    assertThat(node).hasLeaves(1).leavesEqualTo(10);
}