code: private List<String> existingRootFiles() {
          List<String> filesFound = new ArrayList<>();
          for (String path : SU_PATHS) {
              if (new File(path).exists()) {
                  filesFound.add(path);
              }
          }
          return filesFound;
      }
docs: Checks for files that are known to indicate root.
  @return - list of such files found