syntax_data: {"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // means if we have nested spans, the innermost ones will be visited first.
context_before:         // Format and emit explanatory notes about default binding modes. Reversing the spans' order
context_after:         for (span, def_br_mutbl) in self.default_mode_labels.into_iter().rev() {