code: def init_app(self, app=None, blueprint=None, additional_blueprints=None):
          
          if app is not None:
              self.app = app
  
          if blueprint is not None:
              self.blueprint = blueprint
  
          for resource in self.resources:
              self.route(resource['resource'],
                         resource['view'],
                         *resource['urls'],
                         url_rule_options=resource['url_rule_options'])
  
          if self.blueprint is not None:
              self.app.register_blueprint(self.blueprint)
  
          if additional_blueprints is not None:
              for blueprint in additional_blueprints:
                  self.app.register_blueprint(blueprint)
  
          self.app.config.setdefault('PAGE_SIZE', 30)
docs: Update flask application with our api
  
          :param Application app: a flask application