{"ast_node_type":"other","tokens":[{"end":96,"kind":"keyword","start":0,"text":"TyKind::FnDef(def,"}]}
            TyKind::FnDef(def, parameters) => Some(CallableSig::from_def(db, *def, parameters)),
            TyKind::Function(fn_ptr) => Some(CallableSig::from_fn_ptr(fn_ptr)),
            TyKind::Closure(.., substs) => ClosureSubst(substs).sig_ty().callable_sig(db),