Explicitly pass a request object
Get a promise for the next response or error. Note: works best for a queueing service, otherwise may not be the response/error that was triggered by the request.
Optional
matcher: ((req, res) => boolean)matcher If an immediate mode (mergeMap) service, and you need a promise for a specific result, not just the first one, provide a function that takes a request and a response and returns true if the response belongs to that request.
Invoke the service as a function directly (RTK style).