class Character : MonoBehaviour
    {
        void Awake()
        {
            //We need a lot of Bullets, so we need to make sure we have plenty available at all times.
            //Once the object pool contains less than 10 bullets, we should start async instatiation of more,
            //such as to keep up with demand.
            ObjectPool.Instance.SetLowerInstantiationThreshold<Bullet>(10);
        }

        void Update()
        {
            //SHOOOT
            Shoot();
        }

        void Shoot()
        {
            //Gets a bullet from the objectpool.
            //If you want to use the object pool for something that inherits from UnityEngine.Object, 
            //these needs to be available in the Resources folder, and must be unique. In this case, 
            //there must only be one prefab in Resources with the script Bullet attached to it.
            //Having multiple prefabs with the same scripts is undefined behavior.
            //To avoid this, you can use inheritance, and specify, for instance, different kinds of ammunition.
            Bullet b = ObjectPool.Instance.Acquire<Bullet>();

            //Set Bullet position and trajectory
            b.pos = transform.position;
            b.dir = Vector2.up;

            //Make sure that we show the Bullet. Any objects spawned from the objectpool will initially be inactive
            b.gameObject.SetActive(true);
        }
    }

    class Bullet : MonoBehaviour
    {
        public Vector2 pos;
        public Vector2 dir;

        void Update()
        {
            this.pos += dir;
        }

        void OnCollisionEnter(Collision collision)
        {
            //Do something to the target

            ResetAndReturn();
        }

        void ResetAndReturn()
        {
            //Reset the bullet here, though no need to set active to false

            //Return it to the object pool so that it may be recycled.
            ObjectPool.Instance.Release<Bullet>(this);
        }
    }