Bug 126839 [DataBinding] IObservable refactoring
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/Pair.java
* b in the pair (a, b)
	 */
	public final Object b;
	/**
	 * Construct a Pair(a, b)
	 * 
	 * @param a a in the pair (a, b)
	 * @param b b in the pair (a, b)
	 */
	public Pair(Object a, Object b) {
		this.a = a;
		this.b = b;
	}
	/* (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals(Object obj) {
		if (obj.getClass() != Pair.class) {
			return false;
		}
		Pair other = (Pair) obj;
		return a.equals(other.a) && b.equals(other.b);
	}
	/* (non-Javadoc)
	 * @see java.lang.Object#hashCode()
	 */
	public int hashCode() {
		return a.hashCode() + b.hashCode();
	}
}