code: public static int encodeFormatBits(QrCode.ErrorLevel level , int mask ) {
  		int message = (level.value << 3) | (mask & 0xFFFFFFF7);
  		message = message << 10;
  		return message ^ bitPolyModulus(message, FORMAT_GENERATOR,15,5);
  	}
docs: Encodes the format bits. BCH(15,5)
  @param level Error correction level
  @param mask The type of mask that is applied to the qr code
  @return encoded bit field