gMountUnmountFinish with the mount
and GAsyncResult data returned in the callback.
WARNING: g_mount_unmount has been deprecated since version 2.22 and should not be used in newly-written code. Use gMountUnmountWithOperation instead.
gMountUnmount(object, flags = "G_MOUNT_UNMOUNT_NONE", cancellable = NULL, callback, user.data = NULL)objectGMount.flagscancellableGCancellable object, NULL to ignore.callbackGAsyncReadyCallback, or NULL.user.datacallback.