src/vs/editor/common/services/languagesRegistry.ts/LanguagesRegistry/getLanguageIdByLanguageName
class LanguagesRegistry:	public getLanguageIdByLanguageName(languageName: string): string | null {
		const languageNameLower = languageName.toLowerCase();
		if (!hasOwnProperty.call(this._lowercaseNameMap, languageNameLower)) {
			return null;
		}
		return this._lowercaseNameMap[languageNameLower];
	}