public void testPadEnd_null() {
    assertThrows(NullPointerException.class, () -> Strings.padEnd(null, 5, '0'));
  }

  @SuppressWarnings("InlineMeInliner") // test of method that doesn't just delegate
  public void testRepeat() {
    String input = "20";
    assertEquals("", Strings.repeat(input, 0));
    assertEquals("20", Strings.repeat(input, 1));
    assertEquals("2020", Strings.repeat(input, 2));