public Slot(SlotData data, Skeleton skeleton, Bone bone)
 {
     if (data == null)
     {
         throw new ArgumentException ("data cannot be null.");
     }
     if (skeleton == null)
     {
         throw new ArgumentException ("skeleton cannot be null.");
     }
     if (bone == null)
     {
         throw new ArgumentException ("bone cannot be null.");
     }
     this.Data = data;
     this.Skeleton = skeleton;
     this.Bone = bone;
     this.Color = new Color (1, 1, 1, 1);
     this.SetToBindPose ();
 }
        public void AddSlot(SlotData slot)
        {
            if (slot == null)
            {
                throw new ArgumentException ("slot cannot be null.");
            }

            this.slots.Add (slot);
        }