code: func (v *validator) ValidateName(imageName string) error {
  	name := v.ImageName()
  	if name != imageName {
  		return fmt.Errorf("error when reading the app name: %q expected but %q found",
  			imageName, name)
  	}
  	return nil
  }
docs: // ValidateName checks if desired image name is actually the same as
  // the one in the image manifest.