syntax_data: {"ast_node_type":"other","tokens":[{"end":48,"kind":"keyword","start":0,"text":"ty::BorrowKind::Mutable"}]}
source_snippet:                     ty::BorrowKind::Mutable => {
context_before:                     }
context_after:                         BorrowKind::Mut { kind: mir::MutBorrowKind::Default }