src/vs/platform/telemetry/common/telemetryService.ts/TelemetryService/constructor
class TelemetryService:	constructor(
		config: ITelemetryServiceConfig,
		@optional(IConfigurationService) private _configurationService: IConfigurationService
	) {
		this._appender = config.appender;
		this._commonProperties = config.commonProperties || Promise.resolve({});
		this._piiPaths = config.piiPaths || [];
		this._userOptIn = true;
		this._enabled = true;
		this.sendErrorTelemetry = !!config.sendErrorTelemetry;

		// static cleanup pattern for: `file:///DANGEROUS/PATH/resources/app/Useful/Information`
		this._cleanupPatterns = [/file:\/\/\/.*?\/resources\/app\//gi];

		for (let piiPath of this._piiPaths) {
			this._cleanupPatterns.push(new RegExp(escapeRegExpCharacters(piiPath), 'gi'));
		}

		if (this._configurationService) {
			this._updateUserOptIn();
			this._configurationService.onDidChangeConfiguration(this._updateUserOptIn, this, this._disposables);
			type OptInClassification = {
				optIn: { classification: 'SystemMetaData', purpose: 'BusinessInsight', isMeasurement: true };
			};
			type OptInEvent = {
				optIn: boolean;
			};
			this.publicLog2<OptInEvent, OptInClassification>('optInStatus', { optIn: this._userOptIn });

			this._commonProperties.then(values => {
				const isHashedId = /^[a-f0-9]+$/i.test(values['common.machineId']);

				type MachineIdFallbackClassification = {
					usingFallbackGuid: { classification: 'SystemMetaData', purpose: 'BusinessInsight', isMeasurement: true };
				};
				this.publicLog2<{ usingFallbackGuid: boolean }, MachineIdFallbackClassification>('machineIdFallback', { usingFallbackGuid: !isHashedId });
			});
		}
	}