code: def register_signals(self, app):
          
          before_record_index.connect(inject_provisional_community)
          if app.config['COMMUNITIES_OAI_ENABLED']:
              listen(Community, 'after_insert', create_oaipmh_set)
              listen(Community, 'after_delete', destroy_oaipmh_set)
          inclusion_request_created.connect(new_request)
docs: Register the signals.