code: func (ch *Chunk) Done() {
  	if !ch.IsFullyRead() {
  		ch.Drain()
  	}
  	if ch.Wg != nil {
  		ch.Wg.Done()
  	}
  }
docs: // Done signals the parent parser that we are done reading the chunk
  // if the chunk isn't fully read, this code will do so before signaling.