public void Test_TestControl()
{
var testControl = new TestControl {IsValid = true};
const string testPropertyValue = "TEST";
TestControl.SetAdditional(testControl, testPropertyValue);
TestFor.Equality(1, testControl.IsValidCalledCount, "IsValidCalledCount must be 1");
TestFor.Equality(testPropertyValue, TestControl.GetAdditional(testControl), "Additional property must be {0}".FormatWith(testPropertyValue));
}