@Override
 public boolean containsAndAdd(String str) {
   // TODO Auto-generated method stub
   long hash = this.myHashCode(str);
   if (bm.contains(hash)) {
     return true;
   } else {
     bm.add(hash);
   }
   return false;
 }
 @Override
 public boolean contains(String str) {
   // TODO Auto-generated method stub
   long hash = this.myHashCode(str);
   return bm.contains(hash);
 }