code: func (sa *StorageAuthority) GetValidAuthorizations(_ context.Context, regID int64, names []string, now time.Time) (map[string]*core.Authorization, error) {
  	if regID == 1 {
  		auths := make(map[string]*core.Authorization)
  		for _, name := range names {
  			if sa.authorizedDomains[name] || name == "not-an-example.com" {
  				exp := now.AddDate(100, 0, 0)
  				auths[name] = &core.Authorization{
  					Status:         core.StatusValid,
  					RegistrationID: 1,
  					Expires:        &exp,
  					Identifier: core.AcmeIdentifier{
  						Type:  "dns",
  						Value: name,
  					},
  					Challenges: []core.Challenge{
  						{
  							Status: core.StatusValid,
  							ID:     23,
  							Type:   core.ChallengeTypeDNS01,
  						},
  					},
  				}
  			}
  		}
  		return auths, nil
  	} else if regID == 2 {
  		return map[string]*core.Authorization{}, nil
  	} else if regID == 5 || regID == 4 {
  		return map[string]*core.Authorization{"bad.example.com": nil}, nil
  	}
  	return nil, nil
  }
docs: // GetValidAuthorizations is a mock