Support Printing with Order

The children are not printed out in the order as they are defined in the parent. For example, if we have children A, B, C and D in the parent P, the tree looks like this:
      
```
   ┌[D]
   │      
   ├[B]
   │      
[P]┤
   │       
   ├[A]
   │          
   └[C]
```