internal static Arr <ErrorModelType> GetErrorModelTypes(ErrorModelType flags) => _errorModelTypes.Filter(dt => flags.HasFlag(dt));
internal static string SerializeErrorModel(ErrorModelType errorModelType, Arr <object> state) =>
$"{errorModelType}{PROP_SEP}{Join(PROP_SEP, state.Map(o => Convert.ToString(o, InvariantCulture)))}";
public static IErrorModel GetErrorModel(this OutputState outputState, ErrorModelType errorModelType) =>
outputState.ErrorModels
.Find(d => d.ErrorModelType == errorModelType)
.AssertSome($"Failed to find {errorModelType} in error models for {outputState.Name}");
