code: func (r NotRule) Evaluate(headers, query, payload *map[string]interface{}, body *[]byte, remoteAddr string) (bool, error) {
  	rv, err := Rules(r).Evaluate(headers, query, payload, body, remoteAddr)
  	return !rv, err
  }
docs: // Evaluate NotRule will return true if and only if ChildRule evaluates to false