error CS0117: `Util' does not contain a definition for `SetLayerRecursively

I have been trying to follow along with a youtube tutorial by Brackeys. i have used different textures and models than the one in his tutorials. The error " error CS0117: Util' does not contain a definition for SetLayerRecursively" has keep popping up. Any ideas would be appreciated!

using UnityEngine; using UnityEngine.Networking;

public class WeaponManager : NetworkBehaviour {

 [SerializeField]
 private string weaponLayerName = "Weapon";

 [SerializeField]
 private Transform weaponHolder;

 [SerializeField]
 private PlayerWeapon primaryWeapon;

 private PlayerWeapon currentWeapon;
 private WeaponGraphics currentGraphics;

 void Start ()
 {
     EquipWeapon(primaryWeapon);
 }

 public PlayerWeapon GetCurrentWeapon ()
 {
     return currentWeapon;
 }

 public WeaponGraphics GetCurrentGraphics()
 {
     return currentGraphics;
 }

 void EquipWeapon (PlayerWeapon _weapon)
 {
     currentWeapon = _weapon;

     GameObject _weaponIns = (GameObject)Instantiate(_weapon.graphics, weaponHolder.position, weaponHolder.rotation);
     _weaponIns.transform.SetParent(weaponHolder);

     currentGraphics = _weaponIns.GetComponent<WeaponGraphics>();
     if (currentGraphics == null)
         Debug.LogError("No WeaponGraphics component on the weapon object: " + _weaponIns.name);

     if (isLocalPlayer)
         Util.SetLayerRecursively(_weaponIns, LayerMask.NameToLayer(weaponLayerName));

 }

}