public void NotifyItemStackChanged(T item, int difference)
 {
     this.OnItemStackChanged(item, difference);
     ItemsCollection <T> .ItemStackChangedEventHandler itemStackChanged = this.ItemStackChanged;
     if (itemStackChanged != null)
     {
         itemStackChanged(this, item, difference);
     }
 }
 public void NotifyItemRemoved(T item)
 {
     this.OnItemRemoved(item);
     ItemsCollection <T> .ItemRemovedEventHandler itemRemoved = this.ItemRemoved;
     if (itemRemoved != null)
     {
         itemRemoved(this, item);
     }
 }