src/main/java/io/reactivex/Observable.java
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <T> Observable<T> unsafeCreate(ObservableSource<T> onSubscribe) {
        ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
        if (onSubscribe instanceof Observable) {
            throw new IllegalArgumentException("unsafeCreate(Observable) should be upgraded");
        }
        return RxJavaPlugins.onAssembly(new ObservableFromUnsafeSource<T>(onSubscribe));
    }
@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <T> Observable<T> unsafeCreate(ObservableSource<T> onSubscribe) {
        ObjectHelper.requireNonNull(onSubscribe, "onSubscribe is null");
        if (onSubscribe instanceof Observable) {
            throw new IllegalArgumentException("unsafeCreate(Observable) should be upgraded");
        }
        return RxJavaPlugins.onAssembly(new ObservableFromUnsafeSource<T>(onSubscribe));
    }
@ CheckReturnValue @ SchedulerSupport ( SchedulerSupport . NONE ) public static < T > Observable < T > unsafeCreate ( ObservableSource < T > onSubscribe ) { ObjectHelper . requireNonNull ( onSubscribe , "onSubscribe is null" ) ; if ( onSubscribe instanceof Observable ) { throw new IllegalArgumentException ( "unsafeCreate(Observable) should be upgraded" ) ; } return RxJavaPlugins . onAssembly ( new ObservableFromUnsafeSource < T > ( onSubscribe ) ) ; }
Create an Observable by wrapping an ObservableSource <em>which has to be implemented according
to the Reactive-Streams-based Observable specification by handling
disposal correctly; no safeguards are provided by the Observable itself</em>.
<dl>
<dt><b>Scheduler:</b></dt>
<dd>{@code unsafeCreate} by default doesn't operate on any particular {@link Scheduler}.</dd>
</dl>
@param <T> the value type emitted
@param onSubscribe the ObservableSource instance to wrap
@return the new Observable instance
Create an Observable by wrapping an ObservableSource <em > which has to be implemented according to the Reactive - Streams - based Observable specification by handling disposal correctly ; no safeguards are provided by the Observable itself< / em > . <dl > <dt > <b > Scheduler : < / b > < / dt > <dd > {