/**
  This interface specifies queue operations needed in a search.
  The operations are mostly JGL-compliant, but removeFront() is
  used in preference to pop() because its meaning is clearer. 
*/

public interface GeneralQueue {

/**
   Add a new object to the queue.
*/
   public void add(SearchNode object);

/**
   Remove the next object in queue order.
*/
   public SearchNode removeFront();

/**
   Predicate to determine if queue is empty.
*/
   public boolean isEmpty();

}