@CanIgnoreReturnValue
  public final Ordered containsExactly() {
    return containsExactlyEntriesIn(ImmutableMap.of());
  }
@Test
  public void containsExactlyMissingKey() {
    ImmutableMap<String, Integer> actual = ImmutableMap.of("jan", 1, "feb", 2);
    expectFailureWhenTestingThat(actual).containsExactly("jan", 1, "march", 3, "feb", 2);
    assertFailureKeys("missing keys", "for key", "expected value", "---", "expected", "but was");
    assertFailureValue("for key", "march");
    assertFailureValue("expected value", "3");
  }