function CombinedStream() {
        this.writable = false
        this.readable = true
        this.dataSize = 0
        this.maxDataSize = 2 * 1024 * 1024
        this.pauseStreams = true

        this._released = false
        this._streams = []
        this._currentStream = null
      }
Render the prompt to screen
@return {InputPrompt} self