I want to make a function that loops through the children of a tree breadth first.
So first, it will loop through first level of children, and then second level of children, and so on until it reaches the deepest children.
So if the function is applied to the following
It will loop through (L1_a, L1_b, L1_c), then it will proceed to (L2_a, L2_b, L2_c), then finally to (L3_a)
How can I do this?