public static Collection intersection(final Collection a,final Collection b){
  Collection ret=new ArrayList();
  for (  Object object : a) {
    if (b.contains(object)) {
      ret.add(object);
    }
  }
  return ret;
}

public static Collection intersection ( final Collection a , final Collection b ) { Collection ret = new ArrayList ( ) ; for ( Object object : a ) { if ( b . contains ( object ) ) { ret . add ( object ) ; } } return ret ; }
re - implementation of same method from org . apache . commons . collections . collectionutils .
