pub async fn parse_markdown_block(
    markdown: &str,
    language_registry: &Arc<LanguageRegistry>,
    language: Option<Arc<Language>>,
    text: &mut String,
    highlights: &mut Vec<(Range<usize>, MarkdownHighlight)>,
    region_ranges: &mut Vec<Range<usize>>,
    regions: &mut Vec<ParsedRegion>
)