public override PropertyConstraintViolationError Validate(object value, PropertyDefinition propertyDefinition, IPropertyBag propertyBag) { Uri uri = value as Uri; if (uri != null && !this.IsUriOfExpectedKind(uri)) { return(new PropertyConstraintViolationError(DataStrings.ConstraintViolationInvalidUriKind(uri, this.expectedUriKind), propertyDefinition, value, this)); } return(null); }