code: func (r *ResourceDefinition) PreflightPaths() []string {
  	var paths []string
  	r.IterateActions(func(a *ActionDefinition) error {
  		for _, r := range a.Routes {
  			if r.Verb == "OPTIONS" {
  				continue
  			}
  			found := false
  			fp := r.FullPath()
  			for _, p := range paths {
  				if fp == p {
  					found = true
  					break
  				}
  			}
  			if !found {
  				paths = append(paths, fp)
  			}
  		}
  		return nil
  	})
  	r.IterateFileServers(func(fs *FileServerDefinition) error {
  		found := false
  		fp := fs.RequestPath
  		for _, p := range paths {
  			if fp == p {
  				found = true
  				break
  			}
  		}
  		if !found {
  			paths = append(paths, fp)
  		}
  		return nil
  	})
  	return paths
  }
docs: // PreflightPaths returns the paths that should handle OPTIONS requests.