Microsoft.UnitTests.Core.XUnit.MethodFixtures.TaskObserverMethodFixture.ObserveTaskFailure C# (CSharp) Method

        public IDisposable ObserveTaskFailure(Task task) {
            if (task == null) {
                throw new ArgumentNullException(nameof(task));
            }

            return _observedTasks.GetOrAdd(task, t => new Lazy<IDisposable>(() => StartObserving(t))).Value;
        }