code: def _add_auth(self):
          
  
          if not self.auth:
              return
  
          if self.auth and not self.definition_body:
              raise InvalidResourceException(self.logical_id,
                                             "Auth works only with inline Swagger specified in "
                                             "'DefinitionBody' property")
  
          # Make sure keys in the dict are recognized
          if not all(key in AuthProperties._fields for key in self.auth.keys()):
              raise InvalidResourceException(
                  self.logical_id, "Invalid value for 'Auth' property")
  
          if not SwaggerEditor.is_valid(self.definition_body):
              raise InvalidResourceException(self.logical_id, "Unable to add Auth configuration because "
                                                              "'DefinitionBody' does not contain a valid Swagger")
          swagger_editor = SwaggerEditor(self.definition_body)
          auth_properties = AuthProperties(**self.auth)
          authorizers = self._get_authorizers(auth_properties.Authorizers, auth_properties.DefaultAuthorizer)
  
          if authorizers:
              swagger_editor.add_authorizers(authorizers)
              self._set_default_authorizer(swagger_editor, authorizers, auth_properties.DefaultAuthorizer)
  
          # Assign the Swagger back to template
          self.definition_body = swagger_editor.swagger
docs: Add Auth configuration to the Swagger file, if necessary