将observable<list<someobject>>转换为list<someobject>

如何转换:

Observable<List<SomeObject>> to List<SomeObject>

使用此项:

Observable.just(index)
            .map { d ->
                // returns an Observable<List<someObject>>
            }
            .observeOn(Schedulers.computation())
            .map { r ->
                doSomething(r) // r must be converted to a List<someObject>
            }
            .observeOn(AndroidSchedulers.mainThread())
            .take(1)
            .subscribe {
            }