syntax_data: {"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"Mutability::Mut"}]}
source_snippet:         Mutability::Mut => BorrowKind::Mut { kind: MutBorrowKind::Default },
context_before:     match ref_mutability {
context_after:         Mutability::Not => BorrowKind::Shared,