### Question:
GalleryAlbumMediaSubscriptionNotificationBuilder extends AbstractGalleryAlbumUserNotification implements RemoveSenderRecipientBehavior,
    UserSubscriptionNotificationBehavior { GalleryAlbumMediaSubscriptionNotificationBuilder aboutMedia(final Media... medias) { concernedMedia.addAll(Arrays.asList(medias)); return this; } GalleryAlbumMediaSubscriptionNotificationBuilder(final AlbumDetail resource, final User sender);   }### Answer:
@Test void oneMediaAdded() { final GalleryAlbumMediaSubscriptionNotificationBuilder builder = new GalleryAlbumMediaSubscriptionNotificationBuilder( albumDetail, sender); builder.aboutMedia(aMedia()); final UserNotification userNotification = builder.build(); final Map<String, String> titles = computeNotificationTitles(userNotification); assertThat(titles.get(DE), is("Subscription_DE")); assertThat(titles.get(EN), is("Subscription_EN")); assertThat(titles.get(FR), is("Subscription_FR")); final Map<String, String> contents = computeNotificationContents(userNotification); assertThat(contents.get(DE), is("Dem Album <b>A &gt; B</b> wurde ein Medium hinzugefügt.")); assertThat(contents.get(EN), is("A media has been added into album <b>A &gt; B</b>.")); assertThat(contents.get(FR), is("Un média a été ajouté dans l'album <b>A &gt; B</b>.")); }
@Test void severalMediaAdded() { final GalleryAlbumMediaSubscriptionNotificationBuilder builder = new GalleryAlbumMediaSubscriptionNotificationBuilder( albumDetail, sender); builder.aboutMedia(aMedia(), aMedia()); final UserNotification userNotification = builder.build(); final Map<String, String> titles = computeNotificationTitles(userNotification); assertThat(titles.get(DE), is("Subscription_DE")); assertThat(titles.get(EN), is("Subscription_EN")); assertThat(titles.get(FR), is("Subscription_FR")); final Map<String, String> contents = computeNotificationContents(userNotification); assertThat(contents.get(DE), is("Dem Album <b>A &gt; B</b> wurde Medien hinzugefügt.")); assertThat(contents.get(EN), is("Media have been added into album <b>A &gt; B</b>.")); assertThat(contents.get(FR), is("Des médias ont été ajoutés dans l'album <b>A &gt; B</b>.")); }