src/vs/workbench/services/languageDetection/browser/languageDetectionWorkerServiceImpl.ts/LanguageDetectionWorkerClient/detectLanguage
class LanguageDetectionWorkerClient:	public async detectLanguage(resource: URI, langBiases: Record<string, number> | undefined, preferHistory: boolean): Promise<string | undefined> {
		await this._withSyncedResources([resource]);
		return (await this._getProxy()).detectLanguage(resource.toString(), langBiases, preferHistory);
	}