{"ast_node_type":"variable","tokens":[{"end":93,"kind":"keyword","start":0,"text":"let"}]}
                let vtable_entries = self.vtable_entries(receiver_trait.principal(), dyn_ty);
                // looking up the method at index `idx`.
                let Some(ty::VtblEntry::Method(fn_inst)) = vtable_entries.get(idx).copied() else {