code: private OAuthRequest constructXAuthPost(String email, String password) {
          OAuthRequest request = new OAuthRequest(Verb.POST, xauthEndpoint);
          request.addBodyParameter("x_auth_username", email);
          request.addBodyParameter("x_auth_password", password);
          request.addBodyParameter("x_auth_mode", "client_auth");
          return request;
      }
docs: Construct an XAuth request