pkg/flags/strings.go
func (ss *StringsValue) Set(s string) error {
	*ss = strings.Split(s, ",")
	return nil
}
func (ss *StringsValue) Set(s string) error {
	*ss = strings.Split(s, ",")
	return nil
}
// Set parses a command line set of strings, separated by comma.
// Implements "flag.Value" interface.