func (m *MismatchErr) Unwrap() error {
	return ErrMismatchErr
}
Unwrap returns the underlying error cause. This is always ErrMismatchErr so
we can compare any error returned by the batch verifier with errors.Is() but
still retain the context what exactly went wrong.
package order
import (
	"errors"
	"fmt"
	"time"
	"github.com/btcsuite/btcd/btcec"
	"github.com/lightninglabs/lndclient"
	"github.com/lightninglabs/pool/account"
	"github.com/lightninglabs/pool/terms"
)
const (
	deriveKeyTimeout = 10 * time.Second
)
var (
	ErrMismatchErr = errors.New("batch verification result mismatch")
)
type MismatchErr struct {
	msg   string
	cause error
}