question: private void sendAck ( String index , String message , GuacamoleStatus status ) { if ( status != GuacamoleStatus . SUCCESS ) closeInterceptedStream ( index ) ; sendInstruction ( new GuacamoleInstruction ( "ack" , index , message , Integer . toString ( status . getGuacamoleStatusCode ( ) ) ) ) ; }
target:  Injects an "ack" instruction into the outbound Guacamole protocol stream, as if sent by the connected client. "ack" instructions are used to acknowledge the receipt of a stream and its subsequent blobs, and are the only means of communicating success/failure status.