code: func (e ErrCNAMERequired) Error() string {
  	return fmt.Sprintf("acme-dns: new account created for %q. "+
  		"To complete setup for %q you must provision the following "+
  		"CNAME in your DNS zone and re-run this provider when it is "+
  		"in place:\n"+
  		"%s CNAME %s.",
  		e.Domain, e.Domain, e.FQDN, e.Target)
  }
docs: // Error returns a descriptive message for the ErrCNAMERequired instance telling
  // the user that a CNAME needs to be added to the DNS zone of c.Domain before
  // the ACME-DNS hook will work. The CNAME to be created should be of the form:
  //   {{ c.FQDN }} 	CNAME	{{ c.Target }}