code: 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
  }
docs: // delegatedGTLDs filters the provided list of GTLDPeriods removing any entries
  // that were never delegated from the root DNS.