docs: @CanIgnoreReturnValue
    public Ordered containsExactlyEntriesIn(Map<?, ?> expectedMap) {
      if (expectedMap.isEmpty()) {
        if (actual().isEmpty()) {
          return IN_ORDER;
        } else {
          isEmpty(); // fails
          return ALREADY_FAILED;
        }
      }
      boolean containsAnyOrder =
          containsEntriesInAnyOrder(expectedMap, "contains exactly", /* allowUnexpected= */ false);
      if (containsAnyOrder) {
        return new MapInOrder(expectedMap, "contains exactly these entries in order");
      } else {
        return ALREADY_FAILED;
      }
    }