code: function MiddlewareContext (router) {
    events.EventEmitter.call(this);
  
    /**
     * Express routing options (e.g. `caseSensitive`, `strict`).
     * If set to an Express Application or Router, then its routing settings will be used.
     * @type {express#Router}
     */
    this.router = router || {};
  
    /**
     * The parsed Swagger API
     * @type {SwaggerObject}
     */
    this.api = null;
  
    /**
     * The {@link SwaggerParser} instance that was used to parse the API.
     * @type {SwaggerParser}
     */
    this.parser = null;
  
    /**
     * If the Swagger API contains errors, this will be set
     * @type {Error}
     */
    this.error = null;
  }
docs: A context object that is shared by all middleware functions of a {@link Middleware} instance.
  
  @extends EventEmitter
  @constructor