syntax_data: {"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"self.default_mode_labels.insert(default_mode_span,"}]}
source_snippet:             self.default_mode_labels.insert(default_mode_span, default_ref_mutbl);
context_before:             // If this overrides a by-ref default binding mode, label the binding mode.
context_after:             // If our suggestion is to elide redundnt modes, this will be one of them.