cmd/zlint-gtld-update/main.go
func delegatedGTLDs(entries []util.GTLDPeriod) []util.GTLDPeriod {
	var results []util.GTLDPeriod
	for _, gTLD := range entries {
		if gTLD.DelegationDate == "" {
			continue
		}
		results = append(results, gTLD)
	}
	return results
}
func delegatedGTLDs(entries []util.GTLDPeriod) []util.GTLDPeriod {
	var results []util.GTLDPeriod
	for _, gTLD := range entries {
		if gTLD.DelegationDate == "" {
			continue
		}
		results = append(results, gTLD)
	}
	return results
}
// delegatedGTLDs filters the provided list of GTLDPeriods removing any entries
// that were never delegated from the root DNS.