import cn.nukkit.level.sound.ClickSound; //导入依赖的package包/类
@Override
public boolean onActivate(Item item, Player player) {
    if (getMode() == Mode.SUBTRACT) {
        this.meta -= 4;
    } else {
        this.meta += 4;
    }

    this.level.addSound(new ClickSound(this, getMode() == Mode.SUBTRACT ? 0.55F : 0.5F));
    this.level.setBlock(this, this, true, false);
    //bug?

    this.onChange();
    return true;
}
 

import cn.nukkit.level.sound.ClickSound; //导入依赖的package包/类
protected void playOnSound() {
    this.level.addSound(new ClickSound(this, onPitch));
}
 

import cn.nukkit.level.sound.ClickSound; //导入依赖的package包/类
protected void playOffSound() {
    this.level.addSound(new ClickSound(this, offPitch));
}