public ArrayList<Patch> getNeighbors4(){
        ArrayList<Patch> neighbors = new ArrayList();
        if (!topEdge()){
                neighbors.add(getN());
	}
	if (!bottomEdge()){
                neighbors.add(getS());
	}
	if (!leftEdge()){
                neighbors.add(getW());
	}
	if (!rightEdge()){
                neighbors.add(getE());
	}
	return neighbors;
    }