var multithreadedEnvironment = TaskEnvironment.CreateWithProjectDirectoryAndEnvironment(
                GetResolvedTempPath(),
                new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase));

            try
            {
                // Verify system and environement doesn't have the test variable initially
                Environment.GetEnvironmentVariable(testVarName).ShouldBeNull();
                multithreadedEnvironment.GetEnvironmentVariable(testVarName).ShouldBeNull();

                // Set variable in multithreaded environment
                multithreadedEnvironment.SetEnvironmentVariable(testVarName, testVarValue);

                // Multithreaded should have the value but system should not
                multithreadedEnvironment.GetEnvironmentVariable(testVarName).ShouldBe(testVarValue);
                Environment.GetEnvironmentVariable(testVarName).ShouldBeNull();
            }
            finally
            {
                Environment.SetEnvironmentVariable(testVarName, null);
            }