public Map<String, ThemeInfo> getThemesMap() {
    if (themesMap == null) {
      Map<String, ThemeInfo> tmp = new TreeMap<>();
      if (themes != null) {
        for (ThemeInfo theme : themes) {
          tmp.put(theme.getFileName(), theme);
        }
      }
      themesMap = tmp;
    }
    return themesMap;
  }
Set indicator for required restart after a host rack info change.

@param restartRequiredAfterRackChange true if a restart is required
ambari-server/src/main/java/org/apache/ambari/server/state/ServiceInfo.java