/** Called to update the entity's position/logic. */
  public void onUpdate() {
    super.onUpdate();

    if (this.fuel > 0) {
      --this.fuel;
    }

    if (this.fuel <= 0) {
      this.pushX = this.pushZ = 0.0D;
    }

    this.setMinecartPowered(this.fuel > 0);

    if (this.isMinecartPowered() && this.rand.nextInt(4) == 0) {
      this.worldObj.spawnParticle(
          "largesmoke", this.posX, this.posY + 0.8D, this.posZ, 0.0D, 0.0D, 0.0D);
    }
  }
 /** Called to update the entity's position/logic. */
 public void onUpdate() {
   super.onUpdate();
   this.mobSpawnerLogic.updateSpawner();
 }