/// <summary> /// Gets the validation errors for a specified property or for the entire entity. /// </summary> /// <param name="propertyName">The name of the property to retrieve validation errors for, /// or <value>null</value> or <see cref="String.Empty"/> to retrieve entity-level errors.</param> protected override IEnumerable <TError> GetErrors(string propertyName) { return(Errors.AsyncGet(GetErrorsAsync, propertyName)); }