yield return null;
                IEnumerator coro;
                try {
                    coro = Method2();
                }
                catch (Exception ex) {
                    obj._tcs.SetException(ex);
                    yield break;
                }

                while (true)
                {
                    object current = null;
                    try
                    {
                        if (!coro.MoveNext())
                            break;

                        current = coro.Current;
                    }
                    catch (Exception ex)
                    {
                        obj._tcs.SetException(ex);
                        yield break;
                    }
                    
                    yield return current;
                }

                obj.Complete();

                yield return null;
                IEnumerator coro;
                try {
                    coro = Method2();
                }
                catch (Exception ex) {
                    obj._tcs.SetException(ex);
                    yield break;
                }

                while (true)
                {
                    object current = null;
                    try
                    {
                        if (!coro.MoveNext())
                            break;

                        current = coro.Current;
                    }
                    catch (Exception ex)
                    {
                        obj._tcs.SetException(ex);
                        yield break;
                    }
                    
                    yield return current;
                }

                obj.Complete();