按列递归地对未知深度的多维数组中的级别进行排序，同时保留键

问：

为了对现有的多维数组进行排序，我尝试使用 usort，但它不会给我带来任何结果。由于给定的结构，我不能使用嵌套集或类似的东西，因此我必须对其进行排序：

我的阵列：

[
    2 => [
        'position' => 0,
        'children' => [
            3 => ['position' => "375"],
            5 => ['position' => "44"],
            6 => ['position' => "567"],
            9 => [
                'position' =>  "12",
                'children' => [
                    74 => ['position' => "2"],
                    76 => ['position' => "3"],
                    77 => ['position' => "1"],
                ]
            ],
            62 => ['position' => "34"],
            63 => ['position' => "11"],
            66 => ['position' => "114"],
            74 => ['position' => "912"],
            76 => ['position' => "4564"],
        ]
    ]
]

我想按名为“children”的节点对每个级别进行排序。递归应该没有问题。它可以是一个变量结构，其中节点“子节点”可以存在......或不:)

按列值排序后的所需结果：position

[
    2 => [
        'position' => 0,
        'children' => [
            63 => ['position' => "11"],
            9 => [
                'position' =>  "12",
                'children' => [
                    77 => ['position' => "1"],
                    74 => ['position' => "2"],
                    76 => ['position' => "3"],
                ]
            ],
            62 => ['position' => "34"],
            5 => ['position' => "44"],
            66 => ['position' => "114"],
            3 => ['position' => "375"],
            6 => ['position' => "567"],
            74 => ['position' => "912"],
            76 => ['position' => "4564"],
        ]
    ]
]

我尝试了以下代码，但没有成功：

public function recur($data){
        // ...
        foreach($data as $key=>$value){
            if (array_key_exists('children', $value)) {
            usort($value, function ($a, $b): int {
                if ($a['position'] === $b['position']) {
                // ....
                }
                return $a['position'] <=> $b['position'];
            });
        }
    }
}