public void Initialize()

in BASE/src/Microsoft.ApplicationInsights/TelemetryClient.cs [493:591]
78 lines of code
18 McCabe index (conditional complexity)

        public void Initialize(ITelemetry telemetry)
        {
            if (telemetry == null)
            {
                throw new ArgumentNullException(nameof(telemetry));
            }

            ISupportAdvancedSampling telemetryWithSampling = telemetry as ISupportAdvancedSampling;

            // Telemetry can be already sampled out if that decision was made before calling Track()
            bool sampledOut = false;
            if (telemetryWithSampling != null)
            {
                sampledOut = telemetryWithSampling.ProactiveSamplingDecision == SamplingDecision.SampledOut;
            }

            if (!sampledOut)
            {
                if (telemetry is ISupportProperties telemetryWithProperties)
                {
                    if (this.configuration.TelemetryChannel?.DeveloperMode != null && this.configuration.TelemetryChannel.DeveloperMode.Value)
                    {
                        if (!telemetryWithProperties.Properties.ContainsKey("DeveloperMode"))
                        {
                            telemetryWithProperties.Properties.Add("DeveloperMode", "true");
                        }
                    }
                }

                // Properties set of TelemetryClient's Context are copied over to that of ITelemetry's Context
#pragma warning disable CS0618 // Type or member is obsolete
                if (this.Context.PropertiesValue != null)
                {
                    Utils.CopyDictionary(this.Context.Properties, telemetry.Context.Properties);
                }

#pragma warning restore CS0618 // Type or member is obsolete

                // This check avoids accessing the public accessor GlobalProperties
                // unless needed, to avoid the penalty of ConcurrentDictionary instantiation.
                if (this.Context.GlobalPropertiesValue != null)
                {
                    Utils.CopyDictionary(this.Context.GlobalProperties, telemetry.Context.GlobalProperties);
                }

                string instrumentationKey = this.Context.InstrumentationKey;

                if (string.IsNullOrEmpty(instrumentationKey))
                {
                    instrumentationKey = this.configuration.InstrumentationKey;
                }

                telemetry.Context.Initialize(this.Context, instrumentationKey);

                for (int index = 0; index < this.configuration.TelemetryInitializers.Count; index++)
                {
                    try
                    {
                        this.configuration.TelemetryInitializers[index].Initialize(telemetry);
                    }
                    catch (Exception exception)
                    {
                        CoreEventSource.Log.LogError(string.Format(
                                                        CultureInfo.InvariantCulture,
                                                        "Exception while initializing {0}, exception message - {1}",
                                                        this.configuration.TelemetryInitializers[index].GetType().FullName,
                                                        exception));
                    }
                }

                if (telemetry.Timestamp == default(DateTimeOffset))
                {
                    telemetry.Timestamp = PreciseTimestamp.GetUtcNow();
                }

                // Currently backend requires SDK version to comply "name: version"
                if (string.IsNullOrEmpty(telemetry.Context.Internal.SdkVersion))
                {
                    var version = this.sdkVersion ?? (this.sdkVersion = SdkVersionUtils.GetSdkVersion(VersionPrefix));
                    telemetry.Context.Internal.SdkVersion = version;
                }

                // set NodeName to the machine name if it's not initialized yet, if RoleInstance is also not set then we send only RoleInstance
                if (string.IsNullOrEmpty(telemetry.Context.Internal.NodeName) && !string.IsNullOrEmpty(telemetry.Context.Cloud.RoleInstance))
                {
                    telemetry.Context.Internal.NodeName = PlatformSingleton.Current.GetMachineName();
                }

                // set RoleInstance to the machine name if it's not initialized yet
                if (string.IsNullOrEmpty(telemetry.Context.Cloud.RoleInstance))
                {
                    telemetry.Context.Cloud.RoleInstance = PlatformSingleton.Current.GetMachineName();
                }
            }
            else
            {
                CoreEventSource.Log.InitializationIsSkippedForSampledItem();
            }
        }