flatMap kotlin pair.kt

Observable.just("Will")
  .observeOn(Schedulers.io())
  .flatMap({ name ->
    updateUserName.execute(name) //returns another Observable<ApiResult> after calling the API
  }, {
    //this is executed after resolving the last observable emitted, so the result is ready.
     name: String, apiResult: ApiResult -> Pair(name, apiResult) 
  })
  .subscribe({ result ->
    result.first //name
    result.second //apiResult
  })