e the complete event of the txn,
            // so schedule another macro task to execute after that
            //await new Promise(r => setImmediate(r));
            //return;
            // for (let i = 0; i < 1000; i+=1) {
            //         console.log("await...");
            //         await wait();
            //     }
            let p = _resolve(0);
            for (let i=0;i<10;++i) {
                p = _then.call(p, x => x + 1);
            }
            let result = await p;
            co