code: func (call *GetDefaultRichMenuCall) Do() (*RichMenuIDResponse, error) {
  	res, err := call.c.get(call.ctx, APIEndpointDefaultRichMenu, nil)
  	if err != nil {
  		return nil, err
  	}
  	defer closeResponse(res)
  	return decodeToRichMenuIDResponse(res)
  }
docs: // Do method