func HexString2BigInt(str string) (big.Int, error) {
	i := big.Int{}
	_, err := fmt.Sscan("0x"+strings.TrimPrefix(strings.ToLower(str), "0x"), &i)
	return i, err
}
hex string <-> big int
package utils
import (
	"encoding/hex"
	"fmt"
	"github.com/shopspring/decimal"
	"math/big"
	"strconv"
	"strings"
)
func HexString2Int(str string) (int, error) {
	str = strings.ToLower(str)
	i, err := strconv.ParseInt(strings.TrimPrefix(str, "0x"), 16, 64)
	if err != nil {
		return 0, err
	}
	return int(i), nil
}
func Int2HexString(i int) string {
	return fmt.Sprintf("0x%x", i)
}