code: public static String getShortID(String id) {
          String canonicalID = getCanonicalCLDRID(id);
          if (canonicalID == null) {
              return null;
          }
          return getShortIDFromCanonical(canonicalID);
      }
docs: Returns the time zone's short ID for the zone ID.
  For example, "uslax" for zone ID "America/Los_Angeles".
  @param id the time zone ID
  @return the short ID of the time zone ID, or null if the short ID is not available.