return of();
      }
      if (valueComparator != null) {
        if (entriesUsed) {
          alternatingKeysAndValues = Arrays.copyOf(alternatingKeysAndValues, 2 * size);
        }
        sortEntries(alternatingKeysAndValues, size, valueComparator);
      }
      entriesUsed = true;
      return new RegularImmutableBiMap<K, V>(alternatingKeysAndValues, size);
    }

    /**