code: private QrCode.Mode updateModeLogic( QrCode.Mode current , QrCode.Mode candidate )
  	{
  		if( current == candidate )
  			return current;
  		else if( current == QrCode.Mode.UNKNOWN ) {
  			return candidate;
  		} else {
  			return QrCode.Mode.MIXED;
  		}
  	}
docs: If only one mode then that mode is used. If more than one mode is used then set to multiple