MYTREE

And here some code! 👍

		LevelTree tree = new MyArrayListTree(); 
                tree.add("Level-1");
                tree.add("Level-1", "Level-11"); 
                tree.add("Level-1", "Level-12");
                tree.add("Level-1", "Level-13");
                tree.add("Level-12", "Level-121");
                tree.add("Level-12", "Level-122"); 
                tree.add("Level-122","Level-1221"); 
                tree.add("Level-13","Level-132"); 
                tree.add("Level-11","Level-111");
                tree.add("Level-11", "Level-112");