func (b ByteSize) MarshalJSON() ([]byte, error) {
	return []byte(`"` + units.BytesSize(float64(b)) + `"`), nil
}
MarshalJSON returns the size as a JSON string.
package typeutil
import (
	"strconv"
	"github.com/docker/go-units"
	"github.com/pingcap/errors"
)
type ByteSize uint64