code: func (p *PathSpec) PrependBasePath(rel string, isAbs bool) string {
  	basePath := p.GetBasePath(!isAbs)
  	if basePath != "" {
  		rel = filepath.ToSlash(rel)
  		// Need to prepend any path from the baseURL
  		hadSlash := strings.HasSuffix(rel, "/")
  		rel = path.Join(basePath, rel)
  		if hadSlash {
  			rel += "/"
  		}
  	}
  	return rel
  }
docs: // PrependBasePath prepends any baseURL sub-folder to the given resource