{"ast_node_type":"other","tokens":[{"end":93,"kind":"keyword","start":0,"text":"self.tcx.upvars_mentioned(closure_def_id).expect(\"must"}]}
                        self.tcx.upvars_mentioned(closure_def_id).expect("must be an upvar");
                    let upvars =
                    let upvar = upvars[&var_hir_id];