code: func RegisterCallbacks(db *gorm.DB) {
  	callback := db.Callback()
  	if callback.Create().Get("validations:validate") == nil {
  		callback.Create().Before("gorm:before_create").Register("validations:validate", validate)
  	}
  	if callback.Update().Get("validations:validate") == nil {
  		callback.Update().Before("gorm:before_update").Register("validations:validate", validate)
  	}
  }
docs: // RegisterCallbacks register callback into GORM DB