code: func NewControlWriter(dest io.Writer, state ws.State, op ws.OpCode) *ControlWriter {
  	return &ControlWriter{
  		w:     NewWriterSize(dest, state, op, ws.MaxControlFramePayloadSize),
  		limit: ws.MaxControlFramePayloadSize,
  	}
  }
docs: // NewControlWriter contains ControlWriter with Writer inside whose buffer size
  // is at most ws.MaxControlFramePayloadSize + ws.MaxHeaderSize.