Sets (or unsets) the icon on menu_item.
This call is the same as calling gio.icon.Icon.serialize and using the result as the value to gio.menu_item.MenuItem.setAttributeValue for G_MENU_ATTRIBUTE_ICON.
This API is only intended for use with "noun" menu items; things like bookmarks or applications in an "Open With" menu. Don't use it on menu items corresponding to verbs (eg: stock icons for 'Save' or 'Quit').
If icon is null then the icon is unset.
a #GIcon, or null
Sets (or unsets) the icon on menu_item.
This call is the same as calling gio.icon.Icon.serialize and using the result as the value to gio.menu_item.MenuItem.setAttributeValue for G_MENU_ATTRIBUTE_ICON.
This API is only intended for use with "noun" menu items; things like bookmarks or applications in an "Open With" menu. Don't use it on menu items corresponding to verbs (eg: stock icons for 'Save' or 'Quit').
If icon is null then the icon is unset.