src/vs/platform/files/node/diskFileSystemProvider.ts/DiskFileSystemProvider/watchNonRecursive
class DiskFileSystemProvider:	private watchNonRecursive(resource: URI): IDisposable {
		const watcherService = new NodeJSWatcherService(
			this.toFilePath(resource),
			changes => this._onDidChangeFile.fire(toFileChanges(changes)),
			msg => {
				if (msg.type === 'error') {
					this._onDidWatchErrorOccur.fire(msg.message);
				}

				this.logService[msg.type](msg.message);
			},
			this.logService.getLevel() === LogLevel.Trace
		);

		const logLevelListener = this.logService.onDidChangeLogLevel(() => {
			watcherService.setVerboseLogging(this.logService.getLevel() === LogLevel.Trace);
		});

		return combinedDisposable(watcherService, logLevelListener);
	}