code: def parameters(self, parameters, locations=None):
          
          def decorator(func):
              if locations is None and parameters.many:
                  _locations = ('json', )
              else:
                  _locations = locations
              if _locations is not None:
                  parameters.context['in'] = _locations
  
              return self.doc(params=parameters)(
                  self.response(code=HTTPStatus.UNPROCESSABLE_ENTITY)(
                      self.WEBARGS_PARSER.use_args(parameters, locations=_locations)(
                          func
                      )
                  )
              )
  
          return decorator
docs: Endpoint parameters registration decorator.