code: func (res *ResponseRecorder) Write(contents []byte) (int, error) {
  	if res.statusCode == 0 { // if not setted set it here
  		res.WriteHeader(http.StatusOK)
  	}
  	res.chunks = append(res.chunks, contents)
  	return res.underline.Write(contents)
  }
docs: // Write writes the data to the connection as part of an HTTP reply.
  //
  // If WriteHeader has not yet been called, Write calls
  // WriteHeader(http.StatusOK) before writing the data. If the Header
  // does not contain a Content-Type line, Write adds a Content-Type set
  // to the result of passing the initial 512 bytes of written data to
  // DetectContentType.
  //
  // Depending on the HTTP protocol version and the client, calling
  // Write or WriteHeader may prevent future reads on the
  // Request.Body. For HTTP/1.x requests, handlers should read any
  // needed request body data before writing the response. Once the
  // headers have been flushed (due to either an explicit Flusher.Flush
  // call or writing enough data to trigger a flush), the request body
  // may be unavailable. For HTTP/2 requests, the Go HTTP server permits
  // handlers to continue to read the request body while concurrently
  // writing the response. However, such behavior may not be supported
  // by all HTTP/2 clients. Handlers should read before writing if
  // possible to maximize compatibility.