Method error

src/main/java/io/reactivex/rxjava3/core/Flowable.java:2094–2101

Returns a Flowable that invokes a Subscriber's Subscriber#onError onError method when the Subscriber subscribes to it. Backpressu

(@NonNull Supplier<? extends @NonNull Throwable> supplier)

     * @see <a href="http://reactivex.io/documentation/operators/empty-never-throw.html">ReactiveX operators documentation: Throw</a>
     */
    @CheckReturnValue
    @NonNull
    @BackpressureSupport(BackpressureKind.PASS_THROUGH)
    @SchedulerSupport(SchedulerSupport.NONE)
    public static <@NonNull T> Flowable<T> error(@NonNull Supplier<? extends @NonNull Throwable> supplier) {
        Objects.requireNonNull(supplier, "supplier is null");
        return RxJavaPlugins.onAssembly(new FlowableError<>(supplier));
    }

    /**
     * Returns a {@code Flowable} that invokes a {@link Subscriber}'s {@link Subscriber#onError onError} method when the