func (e Enum) ToNumber() float64 {
	return float64(e.Value)
}
ToNumber changes enum index to float64 for numeric operation.
package types
import (
	"strconv"
	"strings"
	"github.com/pingcap/errors"
)
type Enum struct {
	Name  string
	Value uint64
}
func (e Enum) String() string {
	return e.Name
}