public void RegisterInstance_Valid()
{
var helper = new MefHelper();
var instance = new TestClass1()
{
Name = "test"
};
var container = new CompositionContainer();
Assert.IsFalse(container.GetRegistrationInfo(typeof(ITestInterface)));
helper.RegisterInstance(container, typeof(ITestInterface), instance);
Assert.IsTrue(container.GetRegistrationInfo(typeof(ITestInterface)));
Assert.AreEqual(instance, container.ResolveType <ITestInterface>());
}