@Deprecated public static String Collection2String(Collection<?> in,String separator){
  if (in == null) {
    return null;
  }
  return Iterator2String(in.iterator(),separator);
}

@ Deprecated public static String Collection2String ( Collection < ? > in , String separator ) { if ( in == null ) { return null ; } return Iterator2String ( in . iterator ( ) , separator ) ; }
this concatenates the elements of a collection in a string
