public static long count(Bson q,Class<? extends Bean> t){
  String collection=MongoHelper.getCollection(t);
  if (!X.isEmpty(collection)) {
    return count(collection,q);
  }
  return 0;
}

public static long count ( Bson q , Class < ? extends Bean > t ) { String collection = MongoHelper . getCollection ( t ) ; if ( ! X . isEmpty ( collection ) ) { return count ( collection , q ) ; } return 0 ; }
count the data , this may cause big issue if the data is huge
