syntax_data: {"ast_node_type":"other","tokens":[{"end":94,"kind":"keyword","start":0,"text":"///"}]}
source_snippet:     /// Labels for where incompatibility-causing by-ref default binding modes were introduced.
context_before:     pub(crate) binding_mode_count: usize,
context_after:     pub(crate) default_mode_labels: FxIndexMap<Span, ty::Mutability>,