Can you name operators in RxJava that provide parallel execution of multiple requests?

In RxJava, operators that allow running multiple requests in parallel and combining their results are often used. The main ones are:

• flatMap() — transforms elements of the source Observable into Observables and merges them, allowing parallel requests.
• zip() — combines multiple Observables, waiting for an element from each, which can be used for parallel requests with subsequent result merging.
• merge() — merges multiple Observables, emitting elements as they arrive, enabling parallel processing of multiple streams.

Example with flatMap for parallel requests:

Observable.fromIterable(requests)
    .flatMap(request -> api.call(request)
        .subscribeOn(Schedulers.io()))
    .subscribe(result -> {
        // process the result
    });

Here, each request is executed in a separate thread (Scheduler.io()), ensuring parallelism.