code: protected static List<String> buildDefaultTrustedDirs() {
  
      List<String> tDirs = new ArrayList<String>();
      tDirs.add(DEFAULT_VOMS_DIR);
      return tDirs;
    }
docs: Builds a list of trusted directories containing only
  {@link #DEFAULT_VOMS_DIR}.
  
  @return a list of default trusted directory containing the
  {@link #DEFAULT_VOMS_DIR}