def traverse_tree(course):
 queue = [course]
 while (len(queue) > 0):
  node = queue.pop()
  queue.extend(node.get_children())
 return True

def traverse_tree ( course ) : queue = [ course ] while ( len ( queue ) > 0 ) : node = queue . pop ( ) queue . extend ( node . get_children ( ) ) return True
load every descriptor in course .