extensions/markdown-language-features/src/markdownEngine.ts/MarkdownItEngine/tokenizeDocument
class MarkdownItEngine:	private tokenizeDocument(
		document: ITextDocument,
		config: MarkdownItConfig,
		engine: MarkdownIt
	): Token[] {
		const cached = this._tokenCache.tryGetCached(document, config);
		if (cached) {
			this.resetSlugCount();
			return cached;
		}

		this.logger.verbose('MarkdownItEngine', `tokenizeDocument - ${document.uri}`);
		const tokens = this.tokenizeString(document.getText(), engine);
		this._tokenCache.update(document, config, tokens);
		return tokens;
	}