@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public final <R> Observable<R> switchMapSingle(@NonNull Function<? super T, ? extends SingleSource<? extends R>> mapper) {
    """
	Returns a new ObservableSource by applying a function that you supply to each item emitted by the source
	ObservableSource that returns a SingleSource, and then emitting the item emitted by the most recently emitted
	of these SingleSources.
	<p>
	The resulting ObservableSource completes if both the upstream ObservableSource and the last inner SingleSource, if any, complete.
	If the upstream ObservableSource signals an onError, the inner SingleSource is disposed and the error delivered in-sequence.
	<p>
	<img width="640" height="531" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/switchMapSingle.o.png" alt="">
	<dl>
	<dt><b>Scheduler:</b></dt>
	<dd>{@code switchMapSingle} does not operate by default on a particular {@link Scheduler}.</dd>
	</dl>
	<p>History: 2.0.8 - experimental
	@param <R> the element type of the inner SingleSources and the output
	@param mapper
	a function that, when applied to an item emitted by the source ObservableSource, returns a
	SingleSource
	@return an Observable that emits the item emitted by the SingleSource returned from applying {@code func} to the most recently emitted item emitted by the source ObservableSource
	@see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
	@since 2.2
    """
        ObjectHelper.requireNonNull(mapper, "mapper is null");
        return RxJavaPlugins.onAssembly(new ObservableSwitchMapSingle<T, R>(this, mapper, false));
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public final <R> Observable<R> switchMapSingle(@NonNull Function<? super T, ? extends SingleSource<? extends R>> mapper) {
        ObjectHelper.requireNonNull(mapper, "mapper is null");
        return RxJavaPlugins.onAssembly(new ObservableSwitchMapSingle<T, R>(this, mapper, false));
    }
@ CheckReturnValue @ SchedulerSupport ( SchedulerSupport . NONE ) @ NonNull public final < R > Observable < R > switchMapSingle ( @ NonNull Function < ? super T , ? extends SingleSource < ? extends R > > mapper ) { ObjectHelper . requireNonNull ( mapper , "mapper is null" ) ; return RxJavaPlugins . onAssembly ( new ObservableSwitchMapSingle < T , R > ( this , mapper , false ) ) ; }
Returns a new ObservableSource by applying a function that you supply to each item emitted by the source
ObservableSource that returns a SingleSource, and then emitting the item emitted by the most recently emitted
of these SingleSources.
<p>
The resulting ObservableSource completes if both the upstream ObservableSource and the last inner SingleSource, if any, complete.
If the upstream ObservableSource signals an onError, the inner SingleSource is disposed and the error delivered in-sequence.
<p>
<img width="640" height="531" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/switchMapSingle.o.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code switchMapSingle} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>
<p>History: 2.0.8 - experimental
@param <R> the element type of the inner SingleSources and the output
@param mapper
a function that, when applied to an item emitted by the source ObservableSource, returns a
SingleSource
@return an Observable that emits the item emitted by the SingleSource returned from applying {@code func} to the most recently emitted item emitted by the source ObservableSource
@see <a href="http://reactivex.io/documentation/operators/flatmap.html">ReactiveX operators documentation: FlatMap</a>
@since 2.2
Returns a new ObservableSource by applying a function that you supply to each item emitted by the source ObservableSource that returns a SingleSource and then emitting the item emitted by the most recently emitted of these SingleSources . <p > The resulting ObservableSource completes if both the upstream ObservableSource and the last inner SingleSource if any complete . If the upstream ObservableSource signals an onError the inner SingleSource is disposed and the error delivered in - sequence . <p > <img width = 640 height = 531 src = https : // raw . github . com / wiki / ReactiveX / RxJava / images / rx - operators / switchMapSingle . o . png alt = > <dl > <dt > <b > Scheduler : < / b > < / dt > <dd > {