src/vs/platform/telemetry/common/telemetryUtils.ts/configurationTelemetry
export function configurationTelemetry(telemetryService: ITelemetryService, configurationService: IConfigurationService): IDisposable {
	return configurationService.onDidChangeConfiguration(event => {
		if (event.source !== ConfigurationTarget.DEFAULT) {
			type UpdateConfigurationClassification = {
				configurationSource: { classification: 'SystemMetaData'; purpose: 'FeatureInsight' };
				configurationKeys: { classification: 'SystemMetaData'; purpose: 'FeatureInsight' };
			};
			type UpdateConfigurationEvent = {
				configurationSource: string;
				configurationKeys: string[];
			};
			telemetryService.publicLog2<UpdateConfigurationEvent, UpdateConfigurationClassification>('updateConfiguration', {
				configurationSource: ConfigurationTargetToString(event.source),
				configurationKeys: flattenKeys(event.sourceConfig)
			});
		}
	});
}