public class Solution {    private int[] nums;        private Random random;        public Solution(int[] nums)        {            this.nums = nums;            random = new Random();        }        /** Resets the array to its original configuration and return it. */        public int[] Reset()        {            return nums;        }        /** Returns a random shuffling of the array. */        public int[] Shuffle()        {            if (nums == null)            {                return null;            }            int[] a = (int[])nums.Clone();            for (int j = 1; j < a.Length; j++)            {                int i = random.Next(j + 1);                Swap(a, i, j);            }            return a;        }        private void Swap(int[] a, int i, int j)        {            int t = a[i];            a[i] = a[j];            a[j] = t;        }}/** * Your Solution object will be instantiated and called as such: * Solution obj = new Solution(nums); * int[] param_1 = obj.Reset(); * int[] param_2 = obj.Shuffle(); */