assertThat(expected)
        .hasMessageThat()
        .isEqualTo("expected one element but was: <one, two, three, four, five>");
  }

  public void testGetOnlyElement_noDefault_moreThanFiveElements() {
    Iterator<String> iterator = asList("one", "two", "three", "four", "five", "six").iterator();
    IllegalArgumentException expected =