code: function Application(options) {
      if (!(this instanceof Application)) {
          return new Application(options);
      }
      /**
       * Extend Koa
       **/
      koa.call(this);
      this.config = config(options);
      if (enable(this.config, 'logging')){
          logging.logging.configure(this.config.logging);
      }
      parsers(this, this.config.parsers);
  }
docs: Application constructor