public void TestHasFoci()
{
Assert.IsNull(configuration.FociDelegate);
configuration.HasFoci(x => x.Foci);
Assert.IsNotNull(configuration.FociDelegate);
var instance = new TestDocument();
instance.Themes = new string[] { "value1", "value2" };
Assert.IsTrue(Object.ReferenceEquals(instance.Foci, configuration.FociDelegate(instance)));
}