Perform some operations safely.
Typically, errors are thrown out of callbacks and handled altogether. However, some critical sections might not want to have errors leaking, so this middleware ensure that by providing a context where no errors, but status can be raised.
The 'next' continuation is wrapped in such way that if any non-status error is raised, it will be thrown upstream but not leaked from invoking it. This is useful because one only want to deal with errors in the direct scope.