/**
 * Very simple wrapper to contain two values in one object. 
 */ 
public class Pair<T,U> {
	
	/** The first value */
	private T first;
	/** The second value */
	private U second;
	
	/**
	 * Creates a new Pair of values.
	 * @param one The first value.
	 * @param two The second value.
	 */                	
	public Pair(T one, U two){
		this.first = one;
		this.second = two;
	}
	/**
	 * Creates a new Pair of values, both initialized to {@code null}
	 */	 
	public Pair(){ this(null, null); }
	
	/** Returns the first value of this Pair. */     	
	public T getFirst(){ return this.first; }
	/** Sets the first value of this Pair. */
	public void setFirst(T value){ this.first = value; }
	/** Returns the second value of this Pair. */
	public U getSecond(){ return this.second; }
	/** Sets the second value of this Pair. */
	public void setSecond(U value){ this.second = value; }
	/** Returns true iff both values in this Pair are non-null. */
	public boolean allSet(){ return this.first != null && this.second != null; }

}