code: func MultipartForm(req *http.Request, userStruct FieldMapper) error {
  	err := multipartFormBinder(req, userStruct)
  	if len(err) > 0 {
  		return err
  	}
  
  	return nil
  }
docs: // MultipartForm reads a multipart form request and deserializes its data and
  // files into a struct you provide. Files should be deserialized into
  // *multipart.FileHeader fields.