Goのコーディング

	// UTF-8 BOMを追加
	bom := []byte{0xEF, 0xBB, 0xBF} // UTF-8 BOM
	if _, err := file.Write(bom); err != nil {
		return errors.New("failed to write BOM to file")
	}
	if _, err := file.Write(buffer.Bytes()); err != nil {
		return errors.New("failed to write CSV content to file")
	}