@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (!(obj instanceof Pair))
			return false;
		Pair other = (Pair) obj;
		if (fst == null) {
			if (other.fst != null)
				return false;
		} else if (!fst.equals(other.fst))
			return false;
		if (snd == null) {
			if (other.snd != null)
				return false;
		} else if (!snd.equals(other.snd))
			return false;
		return true;
	}