code: func (i UpdateWAFRuleTagStatusInput) validate() error {
  	if i.Tag == "" {
  		return ErrMissingTag
  	}
  	if i.Service == "" {
  		return ErrMissingService
  	}
  	if i.WAF == "" {
  		return ErrMissingWAFID
  	}
  	if i.Status == "" {
  		return ErrMissingStatus
  	}
  	return nil
  }
docs: // validate makes sure the UpdateWAFRuleStatusInput instance has all
  // fields we need to request a change. Almost, but not quite, identical to
  // UpdateWAFRuleStatusInput.validate()