code: public static boolean startsWith(byte[] bytes, byte[] prefix) {
      return bytes != null && prefix != null &&
          bytes.length >= prefix.length &&
          LexicographicalComparerHolder.BEST_COMPARER.
          compareTo(bytes, 0, prefix.length, prefix, 0, prefix.length) == 0;
    }
docs: Return true if the byte array on the right is a prefix of the byte
  array on the left.