gVolumeEjectFinish with the volume
and GAsyncResult returned in the callback.
WARNING: g_volume_eject has been deprecated since version 2.22 and should not be used in newly-written code. Use gVolumeEjectWithOperation instead.
gVolumeEject(object, flags = "G_MOUNT_UNMOUNT_NONE", cancellable = NULL, callback, user.data = NULL)objectGVolume.flagscancellableGCancellable object, NULL to ignore.callbackGAsyncReadyCallback, or NULL.user.datacallback