AsyncRequest lazy initialization

[Alma-media]

AsyncRequest middleware is not supposed to work with lazy initialization, it means that all (final) handlers should be built in advance (and not before the execution) because in that case they are going to have a new request storage per request (asyncJobs)

[Alma-media]

Possible solution: instantiate storage outside middleware function and pass it as an argument.
This argument should be an interface, it will allow replacing timap storage with any other, for instance with sync.Map (without time limit) or custom redis storage.