code: func validateRuntimeClassName(actual *string, validNames []string) field.ErrorList {
  	if actual == nil {
  		return nil // An unset RuntimeClassName is always allowed.
  	}
  
  	for _, valid := range validNames {
  		if valid == policy.AllowAllRuntimeClassNames {
  			return nil
  		}
  		if *actual == valid {
  			return nil
  		}
  	}
  	return field.ErrorList{field.Invalid(field.NewPath("spec", "runtimeClassName"), *actual, "")}
  }
docs: // validates that the actual RuntimeClassName is contained in the list of valid names.