System.Threading.Tests.AsyncLocalTests.NotifyOnThreadContextChange C# (CSharp) Method

        public static async Task NotifyOnThreadContextChange()
        {
            bool expectThreadContextChange = false;
            int expectedPreviousValue = 0;
            int expectedCurrentValue = 1;
            bool gotNotification = false;
            bool expectNotification = false;

            AsyncLocal<int> local = new AsyncLocal<int>(
                args =>
                {
                    gotNotification = true;

                    Assert.True(expectNotification);
                    expectNotification = false;

                    Assert.Equal(args.ThreadContextChanged, expectThreadContextChange);
                    Assert.Equal(args.PreviousValue, expectedPreviousValue);
                    Assert.Equal(args.CurrentValue, expectedCurrentValue);
                });

            expectNotification = true;
            local.Value = 1;
            Assert.True(gotNotification);
            gotNotification = false;

            ExecutionContext ec = ExecutionContext.Capture();

            expectNotification = true;
            expectedPreviousValue = 1;
            expectedCurrentValue = 2;
            local.Value = 2;
            Assert.True(gotNotification);
            gotNotification = false;

            expectNotification = true;
            expectedPreviousValue = 2;
            expectedCurrentValue = 1;
            expectThreadContextChange = true;

            ExecutionContext.Run(
                ec,
                _ =>
                {
                    Assert.True(gotNotification);
                    gotNotification = false;

                    Assert.Equal(local.Value, 1);

                    expectNotification = true;
                    expectedPreviousValue = 1;
                    expectedCurrentValue = 3;
                    expectThreadContextChange = false;
                    local.Value = 3;
                    Assert.True(gotNotification);
                    gotNotification = false;

                    expectNotification = true;
                    expectedPreviousValue = 3;
                    expectedCurrentValue = 2;
                    expectThreadContextChange = true;
                    return;
                },
                null);

            Assert.True(gotNotification);
            gotNotification = false;

            Assert.Equal(local.Value, 2);

            expectNotification = true;
            expectThreadContextChange = true;
            expectedPreviousValue = local.Value;
            expectedCurrentValue = 0;
            return;
        }