Using reflection to call AsyncSubject methods

gistfile1.cs

  	private object InterceptGet(string url, IInvocation invocation)
	{
		var retVal = invocation.Method.ReturnType;
		if (retVal.IsGenericType && retVal.Name == typeof (IObservable<>).Name)
		{
			retVal = retVal.GenericTypeArguments[0];
		}

		var retType = _subjectType.MakeGenericType(retVal);
		var ret = Activator.CreateInstance(retType);

		Observable.Start(() =>
			{
				try
				{
					_client.GetAsync(url).ToObservable().Subscribe(
							x => x.Content.ReadAsStringAsync().ToObservable().Subscribe(
									s =>
										{
											var o = JsonConvert.DeserializeObject(s, retVal);
											retType.GetMethod("OnNext").Invoke(ret, new[] {o});
											retType.GetMethod("OnCompleted", new Type[0]).Invoke(ret, null);
										}
								)
						);
				}
				catch (Exception ex)
				{
					retType.GetMethod("OnError", new [] { typeof(Exception)}).Invoke(ret, new [] { ex });
				}
			}, 
			System.Reactive.Concurrency.NewThreadScheduler.Default
		);

		return ret;
	}