code: func (a AuditLogFilter) String() string {
  	params := "?"
  	if a.ID != "" {
  		params += "&id=" + a.ID
  	}
  	if a.ActorIP != "" {
  		params += "&actor.ip=" + a.ActorIP
  	}
  	if a.ActorEmail != "" {
  		params += "&actor.email=" + a.ActorEmail
  	}
  	if a.ZoneName != "" {
  		params += "&zone.name=" + a.ZoneName
  	}
  	if a.Direction != "" {
  		params += "&direction=" + a.Direction
  	}
  	if a.Since != "" {
  		params += "&since=" + a.Since
  	}
  	if a.Before != "" {
  		params += "&before=" + a.Before
  	}
  	if a.PerPage > 0 {
  		params += "&per_page=" + fmt.Sprintf("%d", a.PerPage)
  	}
  	if a.Page > 0 {
  		params += "&page=" + fmt.Sprintf("%d", a.Page)
  	}
  	return params
  }
docs: // String turns an audit log filter in to an HTTP Query Param
  // list. It will not inclue empty members of the struct in the
  // query parameters.