### Question:
PlayerGamesView { public List<List<String>> getGroupsByRooms() { return getGroupBy(PlayerGame::getRoomName); }  Map<String, GameData> getGamesDataMap(); Map<String, List<String>> getGroupsMap(); List<List<String>> getGroupsByRooms(); List<List<String>> getGroupsByField(); Map<String, Object> getScores(); List<PScoresOf> getScoresForGame(String gameName); List<PScoresOf> getScoresForRoom(String roomName); Map<String, String> getReadableNames();  }### Answer:
@Test public void testGetGroupsByRooms_usersInSeveralGroups_separatedByRooms() { givenUsersInSeveralGroups_withDifferentRooms(); List<List<String>> groups = playerGamesView.getGroupsByRooms(); assertEquals("[[user1, user2], " + "[user3, user4]]", groups.toString()); }
@Test public void testGetGroupsByRooms_usersInSeveralGroups_inOneGeneralGameRoom() { givenUsersInSeveralGroups_inOneGeneralGameRoom(); List<List<String>> groups = playerGamesView.getGroupsByRooms(); assertEquals("[[user1, user2, user3, user4]]", groups.toString()); }