code: public int append(int newByte) {
          int old = buffer2[pos];
          buffer2[pos] = newByte;
          buffer[pos] = cs ? (char) newByte : Character.toLowerCase((char) newByte);
          pos = (++pos < buffer.length) ? pos : 0;
          return old;
      }
docs: Append byte.
  @param newByte the byte
  @return old byte