Lua 表差异键函数

如何检查一个表（作为数组）是否包含另一个表的所有键？ 类似于 PHP 中的 array_diff_key： https://www.php.net/manual/en/function.array-diff-key.php

例如，此函数应返回 ["firstLevel"]["e"]，因为该元素不存在于 tblTwo 中：

tblOne = {
    ["firstLevel"] = {
        ["a"] = "something",
        ["b"] = "something",
        ["c"] = "something",
        ["subLevel"] = {
            ["d"] = "something",
            ["e"] = "something",
        }
    }

tblTwo = {
    ["firstLevel"] = {
        ["a"] = "something",
        ["b"] = "something",
        ["c"] = "something",
        ["subLevel"] = {
            ["d"] = "something",
        }
    }