有一种简单的方法来查询节点的子节点吗？

class Node:
    def __init__(self, value):
        self.value = value
        self.children = []

    def add_child(self, child):
        self.children.append(child)

    def get_children(self):
        return self.children

def get_all_children(node):
    children = node.get_children()
    all_children = []
    for child in children:
        all_children.append(child)
        all_children.extend(get_all_children(child))
    return all_children

# 示例
root = Node("root")
child1 = Node("child1")
child2 = Node("child2")
grandchild1 = Node("grandchild1")
grandchild2 = Node("grandchild2")

root.add_child(child1)
root.add_child(child2)
child1.add_child(grandchild1)
child1.add_child(grandchild2)

all_children = get_all_children(root)
print(all_children)