code: func (ctx *Context) Render(file string, data ...map[string]interface{}) {
  	if ctx.templateLoader == "" {
  		panic(fmt.Errorf("Template loader has not been set"))
  	}
  	var renderData map[string]interface{}
  	if len(data) == 0 {
  		renderData = make(map[string]interface{})
  	} else {
  		renderData = data[0]
  	}
  	renderData["xsrf_token"] = ctx.xsrfToken()
  	content, err := ctx.App.View.Render(ctx.templateLoader, file, renderData)
  	if err != nil {
  		panic(err)
  	}
  	ctx.Send(content)
  }
docs: // Render a template file using the built-in Go template engine.