public static void setAboutHandler( Runnable aboutHandler ) {
		if( !isSupported( Action.APP_ABOUT ) )
			return;

		String handlerClassName;
		if( SystemInfo.isJava_9_orLater )
			handlerClassName = "java.awt.desktop.AboutHandler";
		else if( SystemInfo.isMacOS )
			handlerClassName = "com.apple.eawt.AboutHandler";
		else
			return;

		setHandler( "setAboutHandler", handlerClassName, aboutHandler );
	}
Sets a handler to show a custom About dialog.
<p>
Useful for macOS to enable menu item "MyApp &gt; About".
<p>
Uses:
<ul>
<li>Java 8 on macOS: com.apple.eawt.Application.getApplication().setAboutHandler(com.apple.eawt.AboutHandler)
<li>Java 9+: java.awt.Desktop.getDesktop().setAboutHandler(java.awt.desktop.AboutHandler)
</ul>
flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/FlatDesktop.java