code: func NewWriterSize(w io.Writer, size int) *Writer {
  	return &Writer{
  		wr: bufio.NewWriterSize(w, size),
  		b:  make([]byte, writerBufferSize),
  		tr: unicode.Utf8ToCesu8Transformer,
  	}
  }
docs: // NewWriterSize creates a new Writer instance with given size for bufio.Writer.