code: func (ui *webInterface) source(w http.ResponseWriter, req *http.Request) {
  	args := []string{"weblist", req.URL.Query().Get("f")}
  	rpt, errList := ui.makeReport(w, req, args)
  	if rpt == nil {
  		return // error already reported
  	}
  
  	// Generate source listing.
  	var body bytes.Buffer
  	if err := report.PrintWebList(&body, rpt, ui.options.Obj, maxEntries); err != nil {
  		http.Error(w, err.Error(), http.StatusBadRequest)
  		ui.options.UI.PrintErr(err)
  		return
  	}
  
  	legend := report.ProfileLabels(rpt)
  	ui.render(w, "sourcelisting", rpt, errList, legend, webArgs{
  		HTMLBody: template.HTML(body.String()),
  	})
  }
docs: // source generates a web page containing source code annotated with profile
  // data.