private void append(List l , Node<String> o){
		if(l.size() ==0){
			l.add(o);
		}else{
			boolean did = false;
			for(int j=0;j<l.size();j++){
				int c = this.compare(o.data,((Node<String>)(l.get(j))).data);
				if( c < 0){
					l.add(j, o);
					did = true;
					break;
				}
				if(c == 0){
					did = true;
					break;
				}
			}
			if(!did){
				l.add(o);
			}
		}
	}