new public void Insert(int index, CustomDataItem val) {
			val.SetProject(Project);
			if ( this.Contains(val) ) {
				base.Remove(val);
			}
			base.Insert(index, val);
		}
		new public int Add(CustomDataItem val) {
			val.SetProject(Project);
			if ( !this.Contains(val) ) {
				return base.Add(val);
			}
			return -1;
		}