code: func Append(filename string, b []byte) error {
  	e, err := NewEdit(filename)
  	if err != nil {
  		return err
  	}
  
  	err = e.Append(b)
  	err2 := e.Close()
  	if err != nil {
  		return err
  	}
  	return err2
  }
docs: // * * *
  // Append writes len(b) bytes at the end of the named file. It returns an
  // error, if any. The file is backed up.