code: function MuteStream (opts) {
    Stream.apply(this)
    opts = opts || {}
    this.writable = this.readable = true
    this.muted = false
    this.on('pipe', this._onpipe)
    this.replace = opts.replace
  
    // For readline-type situations
    // This much at the start of a line being redrawn after a ctrl char
    // is seen (such as backspace) won't be redrawn as the replacement
    this._prompt = opts.prompt || null
    this._hadControl = false
  }
docs: var out = new MuteStream(process.stdout) argument auto-pipes