syntax_data: {"ast_node_type":"variable","tokens":[{"end":52,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let source_info = self.source_info(or_span);
context_before:         let or_span = candidate.or_span.unwrap_or(candidate.extra_data.span);
context_after:         let mut last_otherwise = None;