syntax_data: {"ast_node_type":"variable","tokens":[{"end":40,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let patch = MirPatch::new(body);
context_before:     fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
context_after:         let mut checker = SubTypeChecker { tcx, patcher: patch, local_decls: &body.local_decls };