code: function http405 (req, res, next) {
    if (req.swagger && req.swagger.path && !req.swagger.operation) {
      util.debug(
        'Client attempted a %s operation on "%s", which is not allowed by the Swagger API. ' +
        "Returning HTTP 405 (Method Not Allowed)",
        req.method, req.path
      );
  
      // Let the client know which methods are allowed
      let allowedList = util.getAllowedMethods(req.swagger.path);
      res.set("Allow", allowedList);
  
      throw ono({ status: 405 }, "%s does not allow %s. \nAllowed methods: %s",
        req.path, req.method, allowedList || "NONE");
    }
  
    next();
  }
docs: If the Swagger Path was matched, but the HTTP method doesn't match any of the Swagger Operations,
  then an HTTP 405 (Method Not Allowed) error is thrown, and the "Allow" header is set to the list of valid methods