SortedMap<Integer, String> phonePrefixMappings =
GeneratePhonePrefixData.readMappingsFromTextFile(byteArrayInputStream);
GeneratePhonePrefixData.writeToBinaryFile(phonePrefixMappings, byteArrayOutputStream);
// The byte array output stream now contains the corresponding serialized phone prefix map. Try
// to deserialize it and compare it with the initial input.
PhonePrefixMap phonePrefixMap = new PhonePrefixMap();
phonePrefixMap.readExternal(
new ObjectInputStream(new ByteArrayInputStream(byteArrayOutputStream.toByteArray())));
return phonePrefixMap.toString();
}