code: func (r PlaintextErrorResult) Apply(req *Request, resp *Response) {
  	resp.WriteHeader(http.StatusInternalServerError, "text/plain; charset=utf-8")
  	if _, err := resp.GetWriter().Write([]byte(r.Error.Error())); err != nil {
  		resultsLog.Error("Apply: Write error:", "error", err)
  	}
  }
docs: // Apply method is used when the template loader or error template is not available.