animationtimer javafx

1static int speed x ;
2// prefered speed to start with = 5;
3
4new AnimationTimer(){
5  long lastTick = 0;
6  @Override
7  public void handle(long now){
8    if(lastTick == 0 ){
9      frame();
10      lastTick = now ;
11      return;
12    }
13    if(now - lastTick > 1000000000 / speed){
14      frame();
15      lastTick = now;
16    }
17    
18    }
19  }.start();