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