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));
		}