code: function findDriveWwidByIndex(catalog, isEsx, driveIndex) {
          var wwid = null;
          _.forEach(catalog, function(entry) {
              if (entry.identifier === driveIndex) {
                  wwid = isEsx ? entry.esxiWwid : entry.linuxWwid;
                  return false; //have found the result, so we can exit iteration early.
              }
          });
          return wwid;
      }
docs: Search the driveid catalog and lookup the corresponding drive WWID by the input
  drive index.
  @param {Object} catalog - the catalog data of drive id
  @param {Boolean} isEsx - True to return the ESXi formated wwid,
  otherwise linux format wwid.
  @param {Number} driveIndex - The drive index
  @return {String} The WWID for the target drive. If failed, return null