Function isThenable

demo/js/index2.js:2677–2680

(it)

  return S != undefined ? S : C;
};
var isThenable = function(it){
  var then;
  return isObject(it) && typeof (then = it.then) == 'function' ? then : false;
};
var notify = function(record, isReject){
  if(record.n)return;
  record.n = true;