docs: function Child(opts) {
    opts = opts || {}
    BufferedStream.call(this, {concat : opts.concat})
  
    this.writable = true //call Master.child for writable stream
    this.readable = true
  
    this.bufSize = (opts.bufSize === Infinity || !opts.bufSize ? 0 : opts.bufSize) //max bytes before emitting
    this.bufLength = 0 //bytes stored in buffer
  
    this.hasEnded = false
  }