code: def selection_dialog(self, courses):
          
          selected = list(filter(lambda x: x.course.id in self._settings["selected_courses"], courses))
          selection = Picker(
              title="Select courses to download",
              options=courses,
              checked=selected).getSelected()
          if selection:
              self._settings["selected_courses"] = list(map(lambda x: x.course.id, selection))
              self.save()
              log.info("Updated course selection")
docs: opens a curses/picker based interface to select courses that should be downloaded.