Inheritance: TraceFilter
        private void TraceFilterTestHelper(
            Action<ApplicationInsightsTraceListener, TraceEventCache> callTraceEent,
            bool shouldTrace,
            SourceLevels filterLevel = SourceLevels.Warning)
        {
            TraceEventCache shimTraceEventCache = new TraceEventCache();

            using (var traceListener = new ApplicationInsightsTraceListener(this.adapterHelper.InstrumentationKey))
            {
                var telemetryConfiguration = new TelemetryConfiguration
                {
                    InstrumentationKey = Guid.NewGuid().ToString(),
                    TelemetryChannel = this.adapterHelper.Channel
                };

                traceListener.TelemetryClient = new TelemetryClient(telemetryConfiguration);

                var traceFilter = new EventTypeFilter(filterLevel);
                traceListener.Filter = traceFilter;

                callTraceEent(traceListener, shimTraceEventCache);

                Assert.AreEqual(shouldTrace, this.adapterHelper.Channel.SentItems.Length == 1);
            }
        }
 public TestTraceListener()
 {
     Filter = new EventTypeFilter(SourceLevels.All);
 }