src/vs/editor/common/services/languageService.ts/LanguageService/constructor
class LanguageService:	constructor(warnOnOverwrite = false) {
		super();
		LanguageService.instanceCount++;
		this._encounteredLanguages = new Set<string>();
		this._registry = this._register(new LanguagesRegistry(true, warnOnOverwrite));
		this.languageIdCodec = this._registry.languageIdCodec;
		this._register(this._registry.onDidChange(() => this._onDidChange.fire()));
	}