类：stream.PassThrough

【Class: stream.PassThrough】

stream.PassThrough 类是 Transform 流的一个简单实现，它只是将输入字节直接传递到输出。它的主要用途是用于示例和测试，但在某些情况下，stream.PassThrough 作为构建新型流的基础还是很有用的。

【The stream.PassThrough class is a trivial implementation of a Transform stream that simply passes the input bytes across to the output. Its purpose is primarily for examples and testing, but there are some use cases where stream.PassThrough is useful as a building block for novel sorts of streams.】