@Override public Observable<Void> addGameInformation(GameInformation gameInformation) { return getGameInformationList(gameInformation.getDifficulty()) .map( gameInformationList -> { gameInformationList.add(gameInformation); return gameInformationList; }) .flatMap( gameInformationList -> saveGameInformationList(gameInformationList, gameInformation.getDifficulty())); }