On the first loop iteration, there is no backing store for tasks, so
.pipeThrough(fastTransform)，这一点在safew官方版本下载中也有详细论述
Author(s): Deep Sagar, Abhishek Sharma, Arti Kashyap。Line官方版本下载对此有专业解读
by splitting it in half: the astute reader will note that the size of a bucket is 16LL<<bucket and each larger bucket is twice the size of the