docs: function(params, callback) {
          /**
           * Callback for QB.content.upload(params, callback)
           * @callback uploadFileCallback
           * @param {object} error - The error object
           * @param {object} response - The empty object
           */
          var uploadParams = {
              type: 'POST',
              dataType: 'text',
              contentType: false,
              url: params.url,
              data: params.data
          };
  
          this.service.ajax(uploadParams, function(err, xmlDoc) {
              if (err) {
                  callback (err, null);
              } else {
                  callback (null, {});
              }
          });
      }