code: func (h *HTTPBin) RequestWithBody(w http.ResponseWriter, r *http.Request) {
  	resp := &bodyResponse{
  		Args:    r.URL.Query(),
  		Headers: getRequestHeaders(r),
  		Origin:  getOrigin(r),
  		URL:     getURL(r).String(),
  	}
  
  	err := parseBody(w, r, resp)
  	if err != nil {
  		http.Error(w, fmt.Sprintf("error parsing request body: %s", err), http.StatusBadRequest)
  		return
  	}
  
  	body, _ := json.Marshal(resp)
  	writeJSON(w, body, http.StatusOK)
  }
docs: // RequestWithBody handles POST, PUT, and PATCH requests