code: function Favicon_onRequest(api) {
  
          var maxAge = 60 * 60 * 24 * 30 * 12; // one year
  
          api.addHeader('Content-Type', 'image/x-icon');
          api.addHeader('Cache-Control',  'public, max-age=' + ~~(maxAge));
          api.addHeader('ETag', etag(this.file));
  
          if (api.getMethod() !== 'GET') {
              throw new error.HttpError(500, {}, 'Favicon is accessible only via GET request');
          } else if (api.isHeaderCacheUnModified()) {
              api.sendNoChange();
          }
  
          return this.file;
      }
docs: @since 0.0.1
  @author Igor Ivanovic
  @method Favicon#onRequest
  
  @description
  On request handle favicon