{"ast_node_type":"other","tokens":[{"end":43,"kind":"keyword","start":0,"text":"bound_sig:"}]}
    bound_sig: ty::Binder<I, ty::FnSig<I>>,
    cx: I,
) -> Result<(ty::Binder<I, AsyncCallableRelevantTypes<I>>, Vec<I::Predicate>), NoSolution> {