syntax_data: {"ast_node_type":"other","tokens":[{"end":40,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// - `span.lo_or_index == span_data.lo`
context_before: /// Inline-context format (requires non-huge length, non-huge context, and no parent):
context_after: /// - `span.len_with_tag_or_marker == len == span_data.hi - span_data.lo` (must be `<= MAX_LEN`)