@CanIgnoreReturnValue
  public final Ordered containsAtLeast(
      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
    return containsAtLeastEntriesIn(accumulateMultimap(k0, v0, rest));
  }
@Test
  public void containsAtLeastFailureWithEmptyStringMissing() {
    expectFailureWhenTestingThat(ImmutableMultimap.of("key", "value")).containsAtLeast("", "a");
    assertFailureKeys("missing", "---", "expected to contain at least", "but was");
    assertFailureValue("missing", "{\"\" (empty String)=[a]}");
  }