I hope that the implementation of the `check-for-errors!` function that I added to the TrapperkeeperApp in commit 2a85d5d provides a sufficient level of abstraction for the 90% users that you are thinking of.  I'd still prefer to keep the function on the shutdown service a little more granular so it is flexible for testing and other internal plumbing to manipulate in its raw form.  Not sure if you think we need another higher-level function on the shutdown service itself or if what I have now is good enough.