code: func (g *GenOpts) CheckOpts() error {
  	if !filepath.IsAbs(g.Target) {
  		if _, err := filepath.Abs(g.Target); err != nil {
  			return fmt.Errorf("could not locate target %s: %v", g.Target, err)
  		}
  	}
  	if filepath.IsAbs(g.ServerPackage) {
  		return fmt.Errorf("you shouldn't specify an absolute path in --server-package: %s", g.ServerPackage)
  	}
  	if !filepath.IsAbs(g.Spec) && !strings.HasPrefix(g.Spec, "http://") && !strings.HasPrefix(g.Spec, "https://") {
  		if _, err := filepath.Abs(g.Spec); err != nil {
  			return fmt.Errorf("could not locate spec: %s", g.Spec)
  		}
  	}
  	return nil
  }
docs: // CheckOpts carries out some global consistency checks on options.
  //
  // At the moment, these checks simply protect TargetPath() and SpecPath()
  // functions. More checks may be added here.