public static String joinLongs(long[] tokens,String delimiter){
  if (tokens == null)   return "";
  StringBuilder result=new StringBuilder();
  for (int i=0; i < tokens.length; i++) {
    if (i > 0 && delimiter != null) {
      result.append(delimiter);
    }
    result.append(String.valueOf(tokens[i]));
  }
  return result.toString();
}

public static String joinLongs ( long [ ] tokens , String delimiter ) { if ( tokens == null ) return "" ; StringBuilder result = new StringBuilder ( ) ; for ( int i = 0 ; i < tokens . length ; i ++ ) { if ( i > 0 && delimiter != null ) { result . append ( delimiter ) ; } result . append ( String . valueOf ( tokens [ i ] ) ) ; } return result . toString ( ) ; }
concatenates the given long [ ] array into one string , inserting a delimiter between each pair of elements .
