GObject
        GAppLaunchContext
        GInputStream
            GFilterInputStream
                GBufferedInputStream
                    GDataInputStream
            GFileInputStream
            GMemoryInputStream
            GUnixInputStream
        GOutputStream
            GFilterOutputStream
                GBufferedOutputStream
                GDataOutputStream
            GFileOutputStream
            GMemoryOutputStream
            GUnixOutputStream
        GCancellable
        GDesktopAppInfo
        GEmblemedIcon
        GEmblem
        GFileEnumerator
        GFileIcon
        GFileInfo
        GFileMonitor
        GFilenameCompleter
        GTypeModule
            GIOModule
        GMountOperation
        GVolumeMonitor
        GSimpleAsyncResult
        GThemedIcon
        GUnixMountMonitor
        GVfs
    GInterface
        GAppInfo
        GAsyncResult
        GDesktopAppInfoLookup
        GDrive
        GIcon
        GFile
        GLoadableIcon
        GSeekable
        GMount
        GVolume