init(promise, parent)
当构造 promise 时调用。
这不意味着会发生相应的 before
/after
事件,只是存在可能性。
如果在没有获得继续的情况下创建了 promise,则会发生这种情况。
promise
<Promise> The promise being created.parent
<Promise> The promise continued from, if applicable.
Called when a promise is constructed. This does not mean that corresponding
before
/after
events will occur, only that the possibility exists. This will
happen if a promise is created without ever getting a continuation.