pageSaveCallback = function (err) {
        pageBuilder = "";

        if (err) {
          callback(err);
        }

        // update meta properties then continue process by invoking callback
        if (doneWithPartition) {
          callback(null);
        }
        else {
          self.pageIterator.pageIndex++;
          self.saveNextPage(callback);
        }
      }
Helper method used internally to generate and save the next page of the current (dirty) partition.

@param {function} callback - adapter callback to return load result to caller