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// const uniqBy=_.uniqByexport default function subsetsWithDup(nums: number[]): number[][] {    nums.sort((a, b) => a - b);    const ans = [];    const set = new Set<string>();    const n = nums.length;    for (let mask = 0; mask < 2 ** n; ++mask) {        const t = [];        for (let i = 0; i < n; ++i) {            if (mask & (2 ** i)) {                t.push(nums[i]);            }        }
        const str = t.join(",");        if (set.has(str)) {            continue;        } else {            ans.push(t);            set.add(str);        }    }    return ans;}