pkg/flags/unique_urls.go
func NewUniqueURLsWithExceptions(s string, exceptions ...string) *UniqueURLs {
	us := &UniqueURLs{Values: make(map[string]struct{}), Allowed: make(map[string]struct{})}
	for _, v := range exceptions {
		us.Allowed[v] = struct{}{}
	}
	if s == "" {
		return us
	}
	if err := us.Set(s); err != nil {
		plog.Panicf("new UniqueURLs should never fail: %v", err)
	}
	return us
}
func NewUniqueURLsWithExceptions(s string, exceptions ...string) *UniqueURLs {
	us := &UniqueURLs{Values: make(map[string]struct{}), Allowed: make(map[string]struct{})}
	for _, v := range exceptions {
		us.Allowed[v] = struct{}{}
	}
	if s == "" {
		return us
	}
	if err := us.Set(s); err != nil {
		plog.Panicf("new UniqueURLs should never fail: %v", err)
	}
	return us
}
// NewUniqueURLsWithExceptions implements "url.URL" slice as flag.Value interface.
// Given value is to be separated by comma.