* version, which checks package-private methods that we don't want to have to annotate as {@code
   * Nullable} because we don't want diffs from jsr166e.
   */
  public void testNulls() {}

  public void testOverflows() {
    LongAdder longAdder = new LongAdder();
    longAdder.add(Long.MAX_VALUE);
    assertThat(longAdder.sum()).isEqualTo(Long.MAX_VALUE);
    longAdder.add(1);
    // silently overflows; is this a bug?