syntax_data: {"ast_node_type":"other","tokens":[{"end":69,"kind":"keyword","start":0,"text":"pub(crate)"}]}
source_snippet:     pub(crate) default_mode_labels: FxIndexMap<Span, ty::Mutability>,
context_before:     /// Labels for where incompatibility-causing by-ref default binding modes were introduced.
context_after: }