docs: def handle(self, *args, **options):
          """ execute synchronize command """
          self.options = options
          delete = False
  
          try:
              # blank line
              self.stdout.write('\r\n')
              # store verbosity level in instance attribute for later use
              self.verbosity = int(self.options.get('verbosity'))
  
              self.verbose('disabling signals (notififcations, websocket alerts)')
              pause_disconnectable_signals()
  
              self.check_status_mapping()
              self.retrieve_nodes()
              self.extract_users()
              self.import_admins()
              self.import_users()
              self.import_nodes()
              self.check_deleted_nodes()
              self.import_devices()
              self.import_interfaces()
              self.import_links()
              self.check_deleted_links()
              self.import_contacts()
  
              self.confirm_operation_completed()
  
              resume_disconnectable_signals()
              self.verbose('re-enabling signals (notififcations, websocket alerts)')
  
          except KeyboardInterrupt:
              self.message('\n\nOperation cancelled...')
              delete = True
          except Exception as e:
              tb = traceback.format_exc()
              delete = True
              # rollback database transaction
              transaction.rollback()
              self.message('Got exception:\n\n%s' % tb)
              error('import_old_nodeshot: %s' % e)
  
          if delete:
              self.delete_imported_data()