private static int PrintOutput(Executer<Person, StatePopulation> executer)
        {
            var value = executer.Query("CA").Concat(executer.Query("TX")).Sum(x => x.Count);

            var results = executer.Query("CA");
            foreach (var population in results)
            {
                Console.WriteLine(population);
            }

            results = executer.Query("TX");
            foreach (var population in results)
            {
                Console.WriteLine(population);
            }

            Console.WriteLine(value);
            return value;
        }