syntax_data: {"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"hir::ExprKind::AddrOf(hir::BorrowKind::Ref,"}]}
source_snippet:             hir::ExprKind::AddrOf(hir::BorrowKind::Ref, mutbl, arg) => {
context_after:                 ExprKind::Borrow { borrow_kind: mutbl.to_borrow_kind(), arg: self.mirror_expr(arg) }