code: func CalculateRequestSize(buildpackSize int64, bpPath string, fieldName string) (int64, error) {
  	body := &bytes.Buffer{}
  	form := multipart.NewWriter(body)
  
  	bpFileName := filepath.Base(bpPath)
  
  	_, err := form.CreateFormFile(fieldName, bpFileName)
  	if err != nil {
  		return 0, err
  	}
  
  	err = form.Close()
  	if err != nil {
  		return 0, err
  	}
  
  	return int64(body.Len()) + buildpackSize, nil
  }
docs: // tested via the ccv2.buildpack_test.go file at this point