public void testOutputBinaryConfiguration() throws IOException {
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    GeneratePhonePrefixData.outputBinaryConfiguration(AVAILABLE_DATA_FILES, byteArrayOutputStream);
    MappingFileProvider mappingFileProvider = new MappingFileProvider();
    mappingFileProvider.readExternal(
        new ObjectInputStream(new ByteArrayInputStream(byteArrayOutputStream.toByteArray())));
    assertEquals("1|en,en_US,es,\n33|en,fr,\n86|zh_Hans,\n", mappingFileProvider.toString());
  }
  private static Map<Integer, String> parseTextFileHelper(String input) throws IOException {