code: public static <R> FuncN<Observable<R>> asyncFunc(final FuncN<? extends R> func) {
          return toAsync(func);
      }
docs: Convert a synchronous function call into an asynchronous function call through an Observable.
  <p>
  <img width="640" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/asyncFunc.png" alt="">
  <p>
  Alias for toAsync(FuncN) intended for dynamic languages.
  
  @param <R> the result type
  @param func the function to convert
  @return a function that returns an Observable that executes the {@code func} and emits its returned value
  @see <a href="https://github.com/ReactiveX/RxJava/wiki/Async-Operators#wiki-toasync-or-asyncaction-or-asyncfunc">RxJava Wiki: asyncFunc()</a>