func (n NullInt) String() string {
	if !n.Valid {
		return "null"
	}
	return strconv.FormatInt(int64(n.Int), 10)
}
String returns the decimal representation or "null".
package graphql
import (
	"strconv"
	"golang.org/x/xerrors"
)
type Nullable interface {
	IsGraphQLNull() bool
}
func isGraphQLNull(x interface{}) bool {
	n, ok := x.(Nullable)
	return ok && n.IsGraphQLNull()
}
type NullInt struct {
	Int   int32
	Valid bool
}
func (n NullInt) IsGraphQLNull() bool {
	return !n.Valid
}