【Class: stream.Duplex】
stream.Duplex
Instances of Duplex now return true when checking instanceof stream.Writable.
Duplex
true
instanceof stream.Writable
新增于: v0.9.4
双工流是同时实现 Readable 和 Writable 接口的流。
Readable
Writable
【Duplex streams are streams that implement both the Readable and Writable interfaces.】
Duplex 流的例子包括：
【Examples of Duplex streams include:】