UnityEngine.EventSystems.RaycasterManager.AddRaycaster C# (CSharp) Method

        public static void AddRaycaster(BaseRaycaster baseRaycaster)
        {
            if (!s_Raycasters.Contains(baseRaycaster))
            {
                s_Raycasters.Add(baseRaycaster);
            }
        }

 protected override void OnEnable()
 {
     base.OnEnable();
     RaycasterManager.AddRaycaster(this);
 }