QueryDsl instead of MongoTemplate

Could you please help me find out how to include the mongo collection name to a QueryDsl query?

Now I can achieve the functionality I want with mongoTemplate like below:

boolean emailExists(String email) {
    Query query = new Query(Criteria.where(Account.EMAIL).is(email));
    return mongoTemplate.count(query, "accountMethod") > 0;      
}

But I want to do something like this:

boolean emailExists(String email) {
    QAccountMethod accountMethod = new QAccountMethod("accountMethod"); //<---Do I need this?
    final BooleanExpression query = QAccount.account.email.eq(email);
    //  return mongoTemplate.count(query, COLLECTION_NAME) > 0;
}

And I guess instead of using

return mongoTemplate.count(query, COLLECTION_NAME) > 0;

use a repository method?

I was thinking something like that? :

boolean existsAccountByEmail(BooleanExpression query, String collectionName);

that results to this:

boolean emailExists(String email) {
    final BooleanExpression query = QAccount.account.email.eq(email);
        //  return mongoTemplate.count(query, COLLECTION_NAME) > 0;
    return accountRepository.existsAccountByEmail(query, COLLECTION_NAME);
}