public boolean removeAllEdges(Object origin, Object destination)
	{
		// retrieve the origin and destination vertices
		Vertex o = (Vertex)theItems.get(origin);
		Vertex d = (Vertex)theItems.get(destination);
		
		if (o == null || d == null)
		{
			// one of the vertices does not exist
			return false;
		}
		
		// remove all edges from the origin to the destination
		if (!o.adjacencyList.isEmpty())
		{
			for (ListIterator itr = o.adjacencyList.listIterator(0); itr.hasNext(); )
			{
				Edge e = (Edge)itr.getCurrent();
			
				// if Edge to destination exists remove it; otherwise advance
				if (e.destination.equals(d))
					itr.remove();
				else
					itr.next();
			}
		}
		
		// edges successfully removed
		return true;
	}