@Test
public void removeANotFoundElement() {
tree.remove(0);
assertThat(tree.size(), is(6));
List<Integer> list = tree.preorder();
List<Integer> expected = Arrays.asList(2, 1, 4, 3, 5, 6);
assertThat(list, is(equalTo(expected)));
}
@Test
public void removeElement2() {
tree.remove(2);
assertThat(tree.size(), is(5));
List<Integer> list = tree.preorder();
List<Integer> expected = Arrays.asList(3, 1, 5, 4, 6);
assertThat(list, is(equalTo(expected)));
}
@Test
public void checkPreorder() {
List<Integer> list = tree.preorder();
List<Integer> expected = Arrays.asList(2, 1, 4, 3, 5, 6);
assertThat(list, is(equalTo(expected)));
}