Check If Player Is Riding an Entity

Using a run task later scheduler, but can't find if a player is riding an entity.

I know it's something along the lines, p.getEntity().getVehicle() instanceof CustomMob but can't really find it.

 

Just to add onto the question. I would like to check if the player is riding a horse.

 

I tried it out with this:

Code (Text):

public void onTime(final Player p) {
        Bukkit.getScheduler().runTaskLater(Core.getInstance(), new Runnable() {
            @Override
            public void run() {
                if(p.isInsideVehicle()) {
                    if (p.getVehicle() != null) {
                        if (!(p.getVehicle() instanceof Horse)) {
                            Entity entity = p.getVehicle();
                            entity.remove();
                        }
                    }
                }
            }
        },20L);
    }