public void CollectionPerformanceTest() {

            var p = new Persistable<People>(Path);
            Stopwatch watch = new Stopwatch();

            watch.Start();
            for (int i = 0; i < 1000; i++) {
                p.Value.Persons.Add(new Person {
                    FirstName = "Velio",
                    LastName = "Ivanov",
                    Age = 40
                });
                p.Save();
            }
            watch.Stop();

            Console.Out.WriteLine(string.Format("Time elapsed: {0}", watch.Elapsed));
        }