if (currentPassword == null)
throw new NullPointerException("Null currentPassword was passed");
if (newPassword == null)
throw new NullPointerException("Null newPassword was passed");
ChangePasswordParams params = new ChangePasswordParams();
params.setUserName(username);
params.setPassphrase(currentPassword);
params.setNewPassphrase(newPassword);
getMyProxyRep().changePassword(this.credential, params);
}