code: func ParseFiles(fs http.FileSystem, t *template.Template, filenames ...string) (*template.Template, error) {
  	return parseFiles(fs, t, filenames...)
  }
docs: // ParseFiles creates a new Template if t is nil and parses the template definitions from
  // the named files. The returned template's name will have the (base) name and
  // (parsed) contents of the first file. There must be at least one file.
  // If an error occurs, parsing stops and the returned *Template is nil.