private static String concat(Object[] vals,String delim){
  SB sb=new SB();
  boolean first=true;
  for (  Object val : vals) {
    if (!first)     sb.a(delim);
    sb.a(val);
    first=false;
  }
  return sb.toString();
}

private static String concat ( Object [ ] vals , String delim ) { SB sb = new SB ( ) ; boolean first = true ; for ( Object val : vals ) { if ( ! first ) sb . a ( delim ) ; sb . a ( val ) ; first = false ; } return sb . toString ( ) ; }
concat object with delimiter .
