+Validators module provides also the ``validated_handler`` utility which
+makes possible to apply validation also to error_handlers.
+Normally TurboGears would execute @validate based validation only when
+the controller method is called through a request, when you use a controller
+method as the error_handler of another method the error_handler @validate
+gets skipped and arguments are passed as they are.
+Using ``validated_handler`` it is possible to change this behavior and
+apply validation even to error_handlers::
+ from tgext.datahelpers.validators import SQLAEntityConverter, validated_handler
+ return redirect(doc.photo.url)
+In the previous example when calling /photo/3 if document 3 is not available
+it would be retrieved the successive document by calling next. If validated_handler
+gets removed from photo @validate you would get an error as doc wouldn't be an integer.
_validated_handler.decoration = func_.decoration