code: func StreamingResponseWriter(w http.ResponseWriter) *ResponseWriter {
  	fw, err := newFlushWriter(w)
  	if err != nil {
  		panic(err)
  	}
  
  	return &ResponseWriter{
  		ResponseWriter: w,
  		w:              fw,
  	}
  }
docs: // StreamingResponseWriter wraps the http.ResponseWriter with unbuffered
  // streaming. If the provided ResponseWriter does not implement http.Flusher,
  // this function will panic.