Method onError

src/main/java/io/reactivex/rxjava3/core/Emitter.java:41–41

Signal a Throwable exception. @param error the Throwable to signal, not null

(@NonNull Throwable error)

     * @param error the {@code Throwable} to signal, not {@code null}
     */
    void onError(@NonNull Throwable error);

    /**
     * Signal a completion.