Remove async test

Author: stevejgordon

tests/Tests/ClientConcepts/ConnectionPooling/BuildingBlocks/RequestPipelines.doc.cs

@@ -189,77 +189,6 @@ public void FirstUsageCheckConcurrentThreads()
 			semaphoreSlim.CurrentCount.Should().Be(1);
 		}
 
-		// hide
-		[U] public async Task FirstUsageCheckConcurrentThreadsAsync()
-		{
-			//hide
-			var response = new
-			{
-				cluster_name = "elasticsearch",
-				nodes = new
-				{
-					node1 = new
-					{
-						name = "Node Name 1",
-						transport_address = "127.0.0.1:9300",
-						host = "127.0.0.1",
-						ip = "127.0.01",
-						version = "5.0.0-alpha3",
-						build_hash = "e455fd0",
-						roles = new List<string>(),
-						http = new
-						{
-							bound_address = new[] { "127.0.0.1:9200" }
-						},
-						settings = new Dictionary<string, object>
-						{
-							{ "cluster.name", "elasticsearch" },
-							{ "node.name", "Node Name 1" }
-						}
-					}
-				}
-			};
-
-			//hide
-			var responseBody = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(response));
-
-			/** We can demonstrate this with the following example. First, let's configure
-			 * a custom `IConnection` implementation that's simply going to return a known
-			 * 200 response after one second
-			 */
-			var inMemoryConnection = new WaitingInMemoryConnection(
-				TimeSpan.FromSeconds(1),
-				responseBody);
-
-			/**
-			 * Next, we create a <<sniffing-connection-pool, Sniffing connection pool>> using our
-			 * custom connection and a timeout for how long a request can take before the client
-			 * times out
-			 */
-			var sniffingPipeline = CreatePipeline(
-				uris => new SniffingConnectionPool(uris),
-				connection: inMemoryConnection,
-				settingsSelector: s => s.RequestTimeout(TimeSpan.FromSeconds(2)));
-
-			/**Now, with a `SemaphoreSlim` in place that allows only one thread to enter at a time,
-			 * start three tasks that will initiate a sniff on startup.
-			 *
-			 * The first task will successfully sniff on startup with the remaining two waiting
-			 * tasks exiting without exception. The `SemaphoreSlim` is also released, ready for
-			 * when sniffing needs to take place again
-			 */
-			var semaphoreSlim = new SemaphoreSlim(1, 1);
-
-			var task1 = sniffingPipeline.FirstPoolUsageAsync(semaphoreSlim, CancellationToken.None);
-			var task2 = sniffingPipeline.FirstPoolUsageAsync(semaphoreSlim, CancellationToken.None);
-			var task3 = sniffingPipeline.FirstPoolUsageAsync(semaphoreSlim, CancellationToken.None);
-
-			var exception = await Record.ExceptionAsync(async () => await Task.WhenAll(task1, task2, task3));
-
-			exception.Should().BeNull();
-			semaphoreSlim.CurrentCount.Should().Be(1);
-		}
-
 		/**==== Sniff on connection failure */
 		[U]
 		public void SniffsOnConnectionFailure()