code: @Override
    protected final char[] escape(char c) {
      if (c < replacementsLength) {
        char[] chars = replacements[c];
        if (chars != null) {
          return chars;
        }
      }
      if (c >= safeMin && c <= safeMax) {
        return null;
      }
      return escapeUnsafe(c);
    }
docs: Escapes a single character using the replacement array and safe range values. If the given
  character does not have an explicit replacement and lies outside the safe range then {@link
  #escapeUnsafe} is called.