docs: function(params, callback) {
          /**
           * Callback for QB.content.list(params, callback)
           * @callback listOfFilesCallback
           * @param {object} error - The error object
           * @param {object} response - Object with Array of files
           */
          if (typeof params === 'function' && typeof callback === 'undefined') {
              callback = params;
              params = null;
          }
  
          this.service.ajax({url: Utils.getUrl(config.urls.blobs), data: params, type: 'GET'}, function(err,result){
              if (err) {
                  callback(err, null);
              } else {
                  callback (err, result);
              }
          });
      }