{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"debug!(\"annotate_fn_sig:"}]}
        debug!("annotate_fn_sig: did={:?} sig={:?}", did, sig);
    ) -> Option<AnnotatedBorrowFnSignature<'tcx>> {
        let is_closure = self.infcx.tcx.is_closure_like(did.to_def_id());