Find Leaves of Binary Tree

Given a binary tree, collect a tree's nodes as if you were doing this: Collect and remove all leaves, repeat until the tree is empty.

Example:

Input: [1,2,3,4,5]

Output: [[4,5,3],[2],[1]]

Explanation:

Removing the leaves [4,5,3] would result in this tree:
```
   1
  / 
 2          
```
Now removing the leaf [2] would result in this tree:
```
   1          
```
Now removing the leaf [1] would result in the empty tree:
```
   []     
```