void Clicked()
 {
     if (Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift))
     {
         nodeManager.ActivateAdditionalNodes(gameObject.GetComponent <PlayerNode>());
     }
     else
     {
         nodeManager.ActivateSingleNode(gameObject.GetComponent <PlayerNode>());
     }
 }