syntax_data: {"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// whitespace. Returns None if the pattern could not be found or if an error occurred while
context_before:     /// Extends the given `Span` to just after the previous occurrence of `pat` when surrounded by
context_after:     /// retrieving the code snippet.