public static void GetMatchNonMatchTest(
			string headerName, 
			string[] values, 
			bool existsInStore,
			bool expectReturnNull,
			HttpStatusCode expectedStatus = HttpStatusCode.Unused)
		{
			// setup 
			var mocks = new MockRepository();
			var entityTagStore = mocks.StrictMock<IEntityTagStore>();
			var entityTagHandler = new CachingHandler(entityTagStore);
			var request = new HttpRequestMessage(HttpMethod.Get, TestUrl);
			request.Headers.Add(headerName, values);
			TimedEntityTagHeaderValue entityTagHeaderValue = new TimedEntityTagHeaderValue("\"12345678\"");

			if(values.Length>0) // if 
				entityTagStore.Expect(x => x.TryGetValue(Arg<EntityTagKey>.Matches(etg => etg.ResourceUri == entityTagHandler.UriTrimmer(new Uri(TestUrl))),
					out Arg<TimedEntityTagHeaderValue>.Out(entityTagHeaderValue).Dummy)).Return(existsInStore);

			mocks.ReplayAll();


			// run 
			var matchNoneMatch = entityTagHandler.GetIfMatchNoneMatch();
			// verify 
			Task<HttpResponseMessage> resultTask = matchNoneMatch(request);
			Assert.That(expectReturnNull ^ resultTask != null, "result was not as expected");
			if(resultTask!=null && expectedStatus != HttpStatusCode.Unused)
			{
				Assert.AreEqual(expectedStatus, resultTask.Result.StatusCode, "Status code");				
			}
			mocks.VerifyAll();
		}
		public static void TestGetReturnsNullIfVerbNotGet()
		{
			// setup
			var request = new HttpRequestMessage(HttpMethod.Put, TestUrl);
			var entityTagHandler = new CachingHandler();
			var getRule = entityTagHandler.GetIfMatchNoneMatch();
			
			// run
			var task = getRule(request);

			// verify
			Assert.IsNull(task);
		}
		public static void TestGetReturnsBadRequestIfBothIfMatchAndIfNoneMatchExist()
		{
			// setup
			var request = new HttpRequestMessage(HttpMethod.Get, TestUrl);
			request.Headers.Add(HttpHeaderNames.IfMatch, "\"123\"");
			request.Headers.Add(HttpHeaderNames.IfNoneMatch, "\"123\"");
			var entityTagHandler = new CachingHandler();
			var getRule = entityTagHandler.GetIfMatchNoneMatch();

			// run
			var task = getRule(request);
			var httpResponseMessage = task.Result;

			// verify
			Assert.AreEqual(HttpStatusCode.BadRequest, httpResponseMessage.StatusCode);
		}