syntax_data: {"ast_node_type":"function","tokens":[{"end":74,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn visit_statement(&mut self, stmt: &Statement<'tcx>, loc: Location) {
context_before: impl<'tcx> Visitor<'tcx> for ConstMutationChecker<'_, 'tcx> {
context_after:         if let StatementKind::Assign(box (lhs, _)) = &stmt.kind {