@FXML
private void sendData(MouseEvent event) {
  // Step 1
  User u = new User();
  // Step 2
  Node node = (Node) event.getSource();
  // Step 3
  Stage stage = (Stage) node.getScene().getWindow();
  stage.close();
  try {
    // Step 4
    Parent root = FXMLLoader.load(getClass().getClassLoader().getResource("fxml/SceneA.fxml"));
    // Step 5
    stage.setUserData(u);
    // Step 6
    Scene scene = new Scene(root);
    stage.setScene(scene);
    // Step 7
    stage.show();
  } catch (IOException e) {
    System.err.println(String.format("Error: %s", e.getMessage()));
  }
}