public void RenderPeriod()
{
var p = new Period {
Start = "200401"
};
Assert.AreEqual("[200401,∞]", p.ForDisplay());
p.End = "20050212";
Assert.AreEqual("[200401,20050212]", p.ForDisplay());
p.Start = null;
Assert.AreEqual("[∞,20050212]", p.ForDisplay());
}