public String encode(){
  String retval=Long.toString(time);
  retval+=Separators.SP;
  if (sign != null)   retval+=sign;
  retval+=offset.encode();
  return retval;
}

public String encode ( ) { String retval = Long . toString ( time ) ; retval += Separators . SP ; if ( sign != null ) retval += sign ; retval += offset . encode ( ) ; return retval ; }
encode this structure into canonical form .
