code: public void appendChar(int x) {
          elems = ArrayUtils.ensureCapacity(elems, length + 1);
          elems[length  ] = (byte)((x >>  8) & 0xFF);
          elems[length+1] = (byte)((x      ) & 0xFF);
          length = length + 2;
      }
docs: Append a character as a two byte number.