{"ast_node_type":"other","tokens":[{"end":61,"kind":"keyword","start":0,"text":"[coroutine_closure_sig.tupled_inputs_ty],"}]}
                    [coroutine_closure_sig.tupled_inputs_ty],
                let call_sig = self.tcx.mk_fn_sig(
                    coroutine_closure_sig.to_coroutine(