code: func FilterDirEnt(authorizer acl.Authorizer, ent structs.DirEntries) structs.DirEntries {
  	df := dirEntFilter{authorizer: authorizer, ent: ent}
  	return ent[:FilterEntries(&df)]
  }
docs: // FilterDirEnt is used to filter a list of directory entries
  // by applying an ACL policy