public void SerializeToXDocTest()
{
var tested = PersonsList.SerializeToXDoc();
var firstNames = new HashSet <string>(from e in tested.Descendants("FirstName") select e.Value);
var ages = new HashSet <int>(from e in tested.Descendants("Age") select int.Parse(e.Value));
Assert.Equal(5, firstNames.Count);
Assert.Equal(5, ages.Count);
Assert.Contains("Alex", firstNames);
Assert.Contains("Cloe", firstNames);
Assert.Contains("Jack", firstNames);
Assert.Contains("John", firstNames);
Assert.Contains("Grace", firstNames);
Assert.Contains(27, ages);
Assert.Contains(35, ages);
Assert.Contains(45, ages);
Assert.Contains(30, ages);
}