src/vs/workbench/services/textMate/electron-sandbox/textMateWorker.ts/TextMateWorkerModel/_resetTokenization
class TextMateWorkerModel:	private _resetTokenization(): void {
		this._grammar = null;
		this._tokenizationStateStore.flush(null);

		const languageId = this._languageId;
		this._worker.getOrCreateGrammar(languageId).then((r) => {
			if (this._isDisposed || languageId !== this._languageId || !r) {
				return;
			}

			this._grammar = r.grammar;
			this._tokenizationStateStore.flush(r.initialState);
			this._ensureTokens();
		});
	}