private function getKanbanTitle()
 {
     $old_kanban_title = $this->config_manager->getKanbanTitle($this->project_id);
     $kanban_title = trim($this->request->get('kanban-title-admin'));
     if ($kanban_title !== $old_kanban_title) {
         $this->response->kanbanTitleChanged();
     }
     if ($kanban_title == '') {
         $this->response->emptyKanbanTitle();
         $kanban_title = $old_kanban_title;
     }
     return $kanban_title;
 }