code: function requestValidator (context) {
    return [http500, http401, http404, http405, http406, http413, http415];
  
    /**
     * Throws an HTTP 500 error if the Swagger API is invalid.
     * Calling {@link Middleware#init} again with a valid Swagger API will clear the error.
     */
    function http500 (req, res, next) {
      if (context.error) {
        context.error.status = 500;
        throw context.error;
      }
  
      next();
    }
  }
docs: Validates the HTTP request against the Swagger API.
  An error is sent downstream if the request is invalid for any reason.
  
  @param   {MiddlewareContext}    context
  @returns {function[]}