question: private void stop ( ) { if ( this . throttle == null ) { return ; } internalAdjust = true ; throttle . setSpeedSetting ( - 1 ) ; speedSlider . setValue ( 0 ) ; if ( speedSpinner != null ) { speedSpinnerModel . setValue ( Integer . valueOf ( 0 ) ) ; } if ( speedSliderContinuous != null ) { speedSliderContinuous . setValue ( Integer . valueOf ( 0 ) ) ; } internalAdjust = false ; }
target:  Perform an emergency stop.