@SuppressWarnings("unchecked") // safe covariant cast
  static <T extends @Nullable Object> Correspondence<T, T> equality() {
    return (Equality<T>) Equality.INSTANCE;
  }
@Test
  public void testEquality_viaIterableSubjectContains_failure() {
    expectFailure
        .whenTesting()
        .that(ImmutableList.of(1.01, 2.02, 3.03))
        .comparingElementsUsing(equality())
        .contains(2.0);
    // N.B. No "testing whether" fact:
    assertFailureKeys("expected to contain", "but was");
  }