private void setMenuItemState( HMENU systemMenu, int item, boolean enabled ) {
			MENUITEMINFO mii = new MENUITEMINFO();
			mii.cbSize = new UINT( mii.size() );
			mii.fMask = new UINT( MIIM_STATE );
			mii.fType = new UINT( MFT_STRING );
			mii.fState = new UINT( enabled ? MF_ENABLED : MF_DISABLED );
			User32Ex.INSTANCE.SetMenuItemInfo( systemMenu, item, false, mii );
		}
Opens the window's system menu.
The system menu is the menu that opens when the user presses Alt+Space or
right clicks on the title bar
flatlaf-natives/flatlaf-natives-jna/src/main/java/com/formdev/flatlaf/natives/jna/windows/FlatWindowsNativeWindowBorder.java