public GridStringBuilder appendHex(long val){
  String hex=Long.toHexString(val);
  int len=hex.length();
  for (int i=0; i < 16 - len; i++)   a('0');
  a(hex);
  return this;
}

public GridStringBuilder appendHex ( long val ) { String hex = Long . toHexString ( val ) ; int len = hex . length ( ) ; for ( int i = 0 ; i < 16 - len ; i ++ ) a ( '0' ) ; a ( hex ) ; return this ; }
appends given long value as a hex string to this string builder .
