@IsTest
public with sharing class DomainLogicHandlerTest {
    @IsTest
    static void tests() {
        DomainLogicHandler handler = new DomainLogicHandler();
        Account account = new Account();
        handler.check(account);
        handler.check(account, account);
        handler.processRecords();

        System.assert(
            true,
            'Since DomainLogicHandler is a virtual class, there is nothing to assert here.'
        );
    }
}