public void TopKFrequentTest2()
        {
            int[] nums = { 1, 2 };
            int   k    = 2;

            int[] expected = { 1, 2 };
            for (int i = 0; i < expected.Length; i++)
            {
                var result = new TopKFrequentElements().TopKFrequent(nums, k);
                if (!result.Contains(expected[i]))
                {
                    Assert.Fail();
                }
            }

            Assert.Pass();
        }