public void extensions_are_installed()
        {
            IContext   actual    = null;
            IExtension extension = new CallbackExtension(
                delegate(IContext c) {
                actual = c;
            });

            context.Install(extension);
            Assert.That(actual, Is.EqualTo(context));
        }
        public void extension_is_installed_once_for_same_instance()
        {
            int callCount = 0;
            Action <IContext> callback = (Action <IContext>) delegate(IContext ctx) {
                callCount++;
            };
            IExtension extension = new CallbackExtension(callback);

            installer.Install(extension);
            installer.Install(extension);
            Assert.That(callCount, Is.EqualTo(1));
        }