public static String getExternalLevelName(String internal) {
    for (String [] pair : LEVEL_ALIASES) {
      if (pair[INTERNAL_NAME_COLUMN].equals(internal)) {
        return pair[ALIAS_COLUMN];
      }
    }
    // That should never happen
    String message = String.format("Unknown internal " +
            "operation level name %s", internal);
    throw new IllegalArgumentException(message);
  }
Converts internal operation level name to an external alias
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/RequestOperationLevel.java