return v3();
                    }));
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfAbsent_unsupportedPresentExistingValue() {
    try {
      assertEquals(
          "computeIfAbsent(present, returnsCurrentValue) should return present or throw",
          v0(),
          getMap()
              .computeIfAbsent(