assertEquals(
        "getOrDefault(present, null) should return the associated value",
        v0(),
        getMap().getOrDefault(k0(), null));
  }

  public void testGetOrDefault_absent() {
    assertEquals(
        "getOrDefault(absent, def) should return the default value",
        v3(),
        getMap().getOrDefault(k3(), v3()));
  }

  public void testGetOrDefault_absentNullDefault() {