This accessor is useful when developing in DPML- it allows you get the results from asynchronously issue requests using the async accessor. If you are developing an accessor or using a scriping language you may find it easier to use the underlying asynchronous request methods in the NKF API.

If an exception is thrown in the subrequest then the join will propagate that exception. Conversely, if you do not join, an exception or any other result from an asynchronous request will be lost.