public int getIdleExecutors() {
        int r=0;
        for (Computer c : get_all())
            if((c.isOnline() || c.isConnecting()) && c.isAcceptingTasks())
                r += c.countIdle();
        return r;
    }
public int getIdleExecutors ( ) { int r = 0 ; for ( Computer c : get_all ( ) ) if ( ( c . isOnline ( ) || c . isConnecting ( ) ) && c . isAcceptingTasks ( ) ) r += c . countIdle ( ) ; return r ; }
{@code getTotalExecutors()-getBusyExecutors()}, plus executors that are being brought online.