bannersDeletionSubject
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.ui())
    .onErrorReturn { errorBanner }
    .filter { it.id != errorBanner.id }
    .subscribe(
        { banner ->
            val allSectionsWithBanners = ListingSectionRealm()
                .queryAll()
                .filter { section ->
                    section.realmSectionItems.any { it.banner != null && it.banner?.id == banner.id }
                }
                .toList()

            allSectionsWithBanners
                .map { sectionWithBanner ->
                    sectionWithBanner.realmSectionItems.removeAll {
                        it.banner != null && it.banner?.id == banner.id
                    }
                }

            allSectionsWithBanners.saveAll()
        },
        { }
    )