@Override
    public String toString() {
        if (this.head == null) {
        	return "[]";
        }
        
        String answer = "[";
        
        Node ptr;
        for (ptr = this.head; ptr.next != null; ptr = ptr.next) {
            answer += ptr.data + ", ";
        }
        
        answer += ptr.data + "]";
        
        return answer;
    }