How to check that a file is empty

I have recently upgraded Camel to version 2.11.0. In my file transfer
services I have used a predicate together with interceptors to avoid
transferring empty files but instead move them into a subfolder called
"skipped". However, this has stopped working. My predicate looks like this:

*Predicate emptyFile =
PredicateBuilder.toPredicate(SimpleLanguage.simple("${file:length} == 0"));

I'm not exactly sure in what version this functionality broke but I'm sure
it worked in version 2.7.1.

Is there a better way to do this in Camel 2.11.0?

/Bengt