System.Linq.Tests.ExceptTests.EachHasRepeatsBetweenAndAmongstThemselves C# (CSharp) Method

        public void EachHasRepeatsBetweenAndAmongstThemselves()
        {
            int?[] first = { 1, 2, 2, 3, 4, 5 };
            int?[] second = { 5, 3, 2, 6, 6, 3, 1, null, null };
            int?[] expected = { 4 };

            Assert.Equal(expected, first.AsQueryable().Except(second.AsQueryable()));
        }