src/main/java/io/reactivex/Maybe.java
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <R> Maybe<R> map(Function<? super T, ? extends R> mapper) {
        ObjectHelper.requireNonNull(mapper, "mapper is null");
        return RxJavaPlugins.onAssembly(new MaybeMap<T, R>(this, mapper));
    }
@CheckReturnValue
    @NonNull
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <R> Maybe<R> map(Function<? super T, ? extends R> mapper) {
        ObjectHelper.requireNonNull(mapper, "mapper is null");
        return RxJavaPlugins.onAssembly(new MaybeMap<T, R>(this, mapper));
    }
@ CheckReturnValue @ NonNull @ SchedulerSupport ( SchedulerSupport . NONE ) public final < R > Maybe < R > map ( Function < ? super T , ? extends R > mapper ) { ObjectHelper . requireNonNull ( mapper , "mapper is null" ) ; return RxJavaPlugins . onAssembly ( new MaybeMap < T , R > ( this , mapper ) ) ; }
Returns a Maybe that applies a specified function to the item emitted by the source Maybe and
emits the result of this function application.
<p>
<img width="640" height="515" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Maybe.map.png" alt="">
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code map} does not operate by default on a particular {@link Scheduler}.</dd>
</dl>

@param <R> the result value type
@param mapper
a function to apply to the item emitted by the Maybe
@return a Maybe that emits the item from the source Maybe, transformed by the specified function
@see <a href="http://reactivex.io/documentation/operators/map.html">ReactiveX operators documentation: Map</a>
Returns a Maybe that applies a specified function to the item emitted by the source Maybe and emits the result of this function application . <p > <img width = 640 height = 515 src = https : // raw . github . com / wiki / ReactiveX / RxJava / images / rx - operators / Maybe . map . png alt = > <dl > <dt > <b > Scheduler : < / b > < / dt > <dd > { @code map } does not operate by default on a particular { @link Scheduler } . < / dd > < / dl >