code: func (t *Tar) ExcludeRegexp(re *regexp.Regexp, dirOnly bool) {
  	t.ignorePaths = append(t.ignorePaths, ignoreInfo{regexp: re, exclude: true, dirOnly: dirOnly})
  }
docs: // ExcludeRegexp adds a Regexp into the list to consider when selectiong files
  // to exclude. Files or directories matching the regexp will be excluded, even
  // if they matched a previous Regexp from IncludeRegexp. Files are only
  // considered a match if they match the Regexp and isDir is false.