Refactor code.

Tests/MQTTnet.Core.Tests/AsyncAutoResentEvent_Tests.cs

@@ -123,7 +123,7 @@ namespace MQTTnet.Tests
                 waitTask.GetAwaiter().GetResult();
                 Assert.IsTrue(false, "Task was expected to transition to a canceled state.");
             }
-            catch (OperationCanceledException ex)
+            catch (OperationCanceledException)
             {
             }
 

Tests/MQTTnet.Core.Tests/MqttClient_Tests.cs

@@ -68,7 +68,7 @@ namespace MQTTnet.Tests
 
                 var replyReceived = false;
 
-                client1.UseApplicationMessageReceivedHandler(async c =>
+                client1.UseApplicationMessageReceivedHandler(c =>
                 {
                     if (c.ApplicationMessage.Topic == "reply")
                     {