code: public static String getFormatFromFlatFile(File flatFile) {
          if (flatFile == null || !flatFile.exists())
              return null;
  
          try (BufferedReader reader = new BufferedReader(createReader(flatFile))) {
              return getFormatFromFlatFileLine(reader.readLine());
          }
          catch (IOException e) {
              return null;
          }
      }
docs: Returns the NAACCR format of the given flat file, based on it's first data line.
  @param flatFile provided data file
  @return the NAACCR format, null if it cannot be determined