worker.stdout
这是包含工作线程内写入 process.stdout 的数据的可读流。
如果 stdout: true 没有传给 Worker 构造函数，则数据将通过管道传输到父线程的 process.stdout 流。
This is a readable stream which contains data written to process.stdout
inside the worker thread. If stdout: true was not passed to the
Worker constructor, then data will be piped to the parent thread's
process.stdout stream.