code: public synchronized void setUseRedoThread(final boolean useRedoThread) {
  		if (this.useRedoThread && !useRedoThread) { // Stop Redo Thread
  			if (redoThread != null) {
  				stopRedoThread(redoThread);
  			}
  		}
  		this.useRedoThread = useRedoThread;
  	}
docs: Use Dedicated Thread for Redo?
  
  @param useRedoThread (default false)