tree =      A        /   |   \       B    C     D     /   \      /   \    E     F    G     H        /   \   \       I     J    K

["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K"]

class Node:    def __init__(self, name):        self.children = []        self.name = name    def add_child(self, name):        self.children.append(Node(name))        return self    def breadth_first_search(self, array):        # Write your code here.        queue = [self]        while len(queue) > 0:            cur_node = queue.pop(0)            for child in cur_node.children:                queue.append(child)            array.append(cur_node.name)        return array