title: ICON set for JavaFX application is visible in Windows but not in Ubuntu
body: <p>It is a bit weird or maybe there is something wrong with my code.</p>
  
  <p>I am setting JavaFX application ICON which is very well visible on Windows system but not on Ubuntu.</p>
  
  <p><strong>On Windows:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/xXnoK.png" alt="On Taskbar">
  <img src="https://i.stack.imgur.com/ZFEss.png" alt="On Window"></p>
  
  <p><strong>On Ubuntu:</strong></p>
  
  <p><img src="https://i.stack.imgur.com/rk74l.png" alt="On Ubuntu unity-panel"></p>
  
  <p><strong>Any idea about the reason behind this.</strong></p>
  
  <p><strong>Code Sample:</strong></p>
  
  <pre><code>@Override
  public void start(Stage stage) throws Exception {
  
      try {
          setUserAgentStylesheet(STYLESHEET_MODENA);
          FXMLLoader loader = new FXMLLoader();
          Parent root = (Parent) loader.load(getClass().getResourceAsStream("ui/ParentWindow.fxml"));
          final ParentWindowController controller = (ParentWindowController) loader.getController();
  
          stage.addEventHandler(WindowEvent.WINDOW_SHOWN, controller::handleWindowShownEvent);
          stage.addEventHandler(WindowEvent.WINDOW_SHOWING, controller::handleWindowShowingEvent);
          stage.addEventHandler(WindowEvent.WINDOW_CLOSE_REQUEST, controller::handleWindowClosingRequestedEvent);
  
          Scene scene = new Scene(root);
  
          scene.getStylesheets().setAll(
                  getClass().getResource("ui/css/ParentWindow.css").toExternalForm()
          );
  
          stage.setScene(scene);
          stage.initStyle(StageStyle.UNIFIED);
          stage.setResizable(false);
          stage.toFront();
          stage.setTitle("Simple JavaFX Tool");
          stage.getIcons().add(new Image(getClass().getResourceAsStream("resources/images/icon.jpg")));
          stage.show();
      } catch (IOException iOException) {
          iOException.printStackTrace();
      }
  }
  </code></pre>