'git prune'. See the section "NOTES", below.
This runs 'git fsck --unreachable' using all the refs
-available in `$GIT_DIR/refs`, optionally with additional set of
+available in `refs/`, optionally with additional set of
objects specified on the command line, and prunes all unpacked
objects unreachable from any of these head objects from the object database.
In addition, it