policyDBUsersListKey    = "policydb/users/"
	policyDBSTSUsersListKey = "policydb/sts-users/"
	policyDBGroupsListKey   = "policydb/groups/"
)

// splitPath splits a path into a top-level directory and a child item. The
// parent directory retains the trailing slash.
func splitPath(s string, lastIndex bool) (string, string) {
	var i int
	if lastIndex {
		i = strings.LastIndex(s, "/")
	} else {
		i = strings.Index(s, "/")
	}

	err := Remove(path)
	if err == nil || IsNotExist(err) {
		return nil
	}

	// RemoveAll recurses by deleting the path base from
	// its parent directory
	parentDir, base := splitPath(path)

	parent, err := Open(parentDir)
	if IsNotExist(err) {
		// If parent does not exist, base cannot exist. Fail silently
		return nil
	}
	if err != nil {
		return err
	}
	defer parent.Close()