@Override
		public int indexOf(final Object item) {
			if (item == null) {
				for (int index = 0, count = this.size(); index < count; index++) {
					if (this.get(index) == null) return index;
				}
			} else {
				for (int index = 0, count = this.size(); index < count; index++) {
					if (item.equals(this.get(index))) return index;
				}
			}
			return -1;
		}