function setMonarchTokensProvider(languageId, languageDef) {
    const create = (languageDef) => {
        return new MonarchTokenizer(StandaloneServices.get(ILanguageService), StandaloneServices.get(IStandaloneThemeService), languageId, compile(languageId, languageDef), StandaloneServices.get(IConfigurationService));
    };
    if (isThenable(languageDef)) {
        return registerTokensProviderFactory(languageId, { create: () => languageDef });
    }
    return languages.TokenizationRegistry.register(languageId, create(languageDef));
}
Set the tokens provider for a language (monarch implementation). This tokenizer will be exclusive
with a tokenizer set using `setTokensProvider`, or with `registerTokensProviderFactory`, but will
work together with a tokens provider set using `registerDocumentSemanticTokensProvider` or
`registerDocumentRangeSemanticTokensProvider`.