protected Put updateUser(String key,
String userName, String password,
String firstName, String lastName, String email,
String authenticationUserName, String authenticationPassword) throws IOException, JAXBException {
String xml = createUserXml(userName, password, firstName, lastName, email);
Put request = new Put(USERS_URL + key + GPX_URL_POSTFIX, new SimpleCredentials(authenticationUserName, authenticationPassword));
request.addFile("file", xml.getBytes());
return request;
}