src/main/java/io/reactivex/Completable.java
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Completable onErrorResumeNext(final Function<? super Throwable, ? extends CompletableSource> errorMapper) {
        ObjectHelper.requireNonNull(errorMapper, "errorMapper is null");
        return RxJavaPlugins.onAssembly(new CompletableResumeNext(this, errorMapper));
    }
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Completable onErrorResumeNext(final Function<? super Throwable, ? extends CompletableSource> errorMapper) {
        ObjectHelper.requireNonNull(errorMapper, "errorMapper is null");
        return RxJavaPlugins.onAssembly(new CompletableResumeNext(this, errorMapper));
    }
Returns a Completable instance that when encounters an error from this Completable, calls the
specified mapper function that returns another Completable instance for it and resumes the
execution with it.
<p>
<img width="640" height="426" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Completable.onErrorResumeNext.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code onErrorResumeNext} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>
@param errorMapper the mapper function that takes the error and should return a Completable as
continuation.
@return the new Completable instance