code: function get ( url, async, cb, cbError ) {
          var data,
              request = new XMLHttpRequest;
  
          request.open( 'GET', url, async );
  
          request.onload = function () {
              if ( this.status >= 200 && this.status < 400 ) {
                  // Success!
                  data = this.response;
              } else {
                  // We reached our target server, but it returned an error. Most likely, the bower.json file is missing.
                  // We just return undefined here.
                  data = undefined;
              }
              cb( data );
          };
  
          request.onerror = function ( err ) {
              // There was a connection error of some sort.
              if ( cbError ) cbError( err );
          };
  
          request.send();
      }
docs: Helper functions in the absence of a library like jQuery (not loaded at this point)