private JsonToken mToken;
public JWTAuthToken(String networkName, String networkSecret,
String userId, String displayName, double expires)
throws InvalidKeyException {
HmacSHA256Signer signer = new HmacSHA256Signer(null, null,
networkSecret.getBytes());
mToken = new JsonToken(signer);
JsonObject tokenJSON = mToken.getPayloadAsJsonObject();
tokenJSON.addProperty("domain", networkName);
tokenJSON.addProperty("user_id", userId);