Window icon not applied to OptionPane

[TheCardinalSystem]

I want to display a custom window icon on some of my option panes, so I created a custom method which takes an Image parameter and shows a JOptionPane:

public static int showOptionDialog(Component parentComponent, Object message, String title, int optionType,
        int messageType, Icon icon, Image windowIcon, Object[] options, Object initialValue)
        throws HeadlessException {
    JOptionPane pane = new JOptionPane(message, messageType, optionType, icon, options, initialValue);
    pane.setInitialValue(initialValue);

    JDialog dialog = pane.createDialog(parentComponent, title);
    pane.selectInitialValue();

    dialog.setIconImage(windowIcon);
    dialog.show();
    dialog.dispose();

    Object selectedValue = pane.getValue();

    if (selectedValue == null)
        return JOptionPane.CLOSED_OPTION;
    if (options == null) {
        if (selectedValue instanceof Integer)
            return ((Integer) selectedValue).intValue();
        return JOptionPane.CLOSED_OPTION;
    }
    for (int counter = 0, maxCounter = options.length; counter < maxCounter; counter++) {
        if (options[counter].equals(selectedValue))
            return counter;
    }
    return JOptionPane.CLOSED_OPTION;
}

This works when using a built-in LAF, but when I switch to FlatLaf the icon vanishes. I discovered the TitlePane.icon key from this issue, but this affects all option panes. I only want to set icons on specific option panes, and these icons will differ depending on the information displayed.

Can FlatLaf be modified to acknowledge icons set with setIconImages?

[DevCharly]

You can show icon for single (JOptionPane) dialog with:

dialog.getRootPane().putClientProperty( FlatClientProperties.TITLE_BAR_SHOW_ICON, true );

Or show icon for all JOptionPanes with:

UIManager.put( "OptionPane.showIcon", true );