src/vs/editor/common/tokens/lineTokens.ts/LineTokens/getLanguageId
class LineTokens:	public getLanguageId(tokenIndex: number): string {
		const metadata = this._tokens[(tokenIndex << 1) + 1];
		const languageId = TokenMetadata.getLanguageId(metadata);
		return this._languageIdCodec.decodeLanguageId(languageId);
	}