code: public int read()
      throws IOException
    {
      if (_byteHead == _byteTail) {
        return -1;
      }
  
      int b = _byteBuffer[_byteTail] & 0xff;
      _byteTail = (_byteTail + 1) % _byteBuffer.length;
  
      return b;
    }
docs: For internal use only.  Reads the next byte from the byte buffer.
  
  @return the next byte