AcManager.Controls.Dialogs.Prompt.ViewModel.GetErrors C# (CSharp) Метод

            public IEnumerable GetErrors(string propertyName) {
                switch (propertyName) {
                    case nameof(Text):
                        return Required && string.IsNullOrWhiteSpace(Text) ? new[] { "Required value" } : null;
                    default:
                        return null;
                }
            }