syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// vast majority (99.9%+) of `SpanData` instances can be made to fit within
context_before: /// takes up 8 bytes, with less space for the length, parent and context. The
context_after: /// those 8 bytes. Any `SpanData` whose fields don't fit into a `Span` are