code: def stop_all(self):
          
          logger.info('Shutting down modules...')
          # Ask internal to quit if they can
          for instance in self.get_internal_instances():
              if hasattr(instance, 'quit') and isinstance(instance.quit, collections.Callable):
                  instance.quit()
  
          self.clear_instances([instance for instance in self.instances if instance.is_external])
docs: Stop all module instances
  
          :return: None