@TraitName("test")
public class TestTrait extends Trait {

    protected TestTrait() {
        super("test");
    }

    @EventHandler
    public void click(NPCRightClickEvent event){
        if(event.getNPC().equals(this.getNPC())) {
            Bukkit.getConsoleSender().sendMessage("yay it works");
        }
    }

}

in my plugin class:
@Override
public void onEnable() {
   CitizensAPI.getTraitFactory().registerTrait(TraitInfo.create(TestTrait.class));
}