code: public JsonObject validateTokenToJson(String token) throws GitkitClientException {
      if (token == null) {
        return null;
      }
      try {
        return tokenHelper.verifyAndDeserialize(token).getPayloadAsJsonObject();
      } catch (SignatureException e) {
        throw new GitkitClientException(e);
      }
    }
docs: Verifies a Gitkit token.
  
  @param token token string to be verified.
  @return the JSON object for the payload of the token if the token is valid.
  @throws GitkitClientException if token has invalid signature