anchor.diff:  
       return firstName == firstName2 && lastName == lastName2;
     }
  +
  +  /// Filter the passed notice board [entries] by the passed [filterString].
  +  List<NoticeBoardEntry> _filterEntries(List<NoticeBoardEntry> entries, String filterString) {
  +    filterString = filterString.toLowerCase();
  +
  +    return entries
  +        .where((entry) =>
  +            entry.title.toLowerCase().contains(filterString) ||
  +            entry.author.toLowerCase().contains(filterString) ||
  +            entry.content.toLowerCase().contains(filterString))
  +        .toList(growable: false);
  +  }
   }
  
positive.code:           if (snapshot.hasData) {
              List<NoticeBoardEntry> entries = snapshot.data[0];
              List<HMPerson> hmPeople = snapshot.data[1];
  
              sliverList = SliverList(delegate: SliverChildBuilderDelegate(
                (BuildContext context, int index) {
  
negative.code: import 'package:guide7/model/hm_people/hm_person.dart';
  import 'package:guide7/model/notice_board/notice_board_entry.dart';
  import 'package:guide7/ui/view/notice_board/entry/notice_board_entry_widget.dart';
  import 'package:guide7/util/custom_colors.dart';
  
  /// View showing the notice board.
  class NoticeBoardView extends StatefulWidget {
  