code: function (directory) {
          // Globs match root level only
          var extMatches = glob.sync(this.getExtensionGlob(this.getExtensions(), ROOT_ONLY), {cwd: directory}),
              dirMatches = glob.sync(this.getDirectoryGlob(this.getDirectories(), ROOT_ONLY), {cwd: directory}),
              extMatchesAll;
  
          // There is no base directory
          if (extMatches.length > 0 || dirMatches.length > 0) {
              return;
          }
          // There is a base directory, grab it from any ext match
          extMatchesAll = glob.sync(
              this.getExtensionGlob(this.getExtensions(), ALL_DIRS), {cwd: directory}
          );
          if (extMatchesAll.length < 1 || extMatchesAll[0].split('/') < 1) {
              throw new common.errors.ValidationError({message: common.i18n.t('errors.data.importer.index.invalidZipFileBaseDirectory')});
          }
  
          return extMatchesAll[0].split('/')[0];
      }
docs: Get the name of the single base directory if there is one, else return an empty string
  @param {String} directory
  @returns {Promise (String)}