code: def _fetch_contribution_info(self):
          
          self.contributions = {}
          query = (Contribution.query
                   .with_parent(self.event)
                   .options(joinedload('legacy_mapping'),
                            joinedload('timetable_entry').lazyload('*')))
          for contribution in query:
              if not contribution.start_dt:
                  continue
              cid = (contribution.legacy_mapping.legacy_contribution_id if contribution.legacy_mapping
                     else contribution.id)
              key = '{}t{}'.format(contribution.event_id, cid)
              self.contributions[key] = u'{} ({})'.format(contribution.title,
                                                          to_unicode(format_time(contribution.start_dt)))
docs: Build the list of information entries for contributions of the event