@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			Node<?> other = (Node<?>) obj;
			if (data == null) {
				if (other.data != null)
					return false;
			} else if (!data.equals(other.data))
				return false;
			return true;
		}