/// <summary>
    /// Create bullet prefab
    /// </summary>
    /// <returns>bullet prefab game object</returns>
    public GameObject CreateBulletPrefab()
    {
        GameObject prefab = CreateGameObject();

        prefab.Name = "Bullet";
        Bullet         component = prefab.AddComponent <Bullet>();
        SphereCollider collider  = prefab.AddComponent <SphereCollider>();

        collider.SetSize(0.25f);
        prefab.SetActive(false);
        return(prefab);
    }