Well, they could be enabled, but they'd test nothing because for the moment I've said byte[] are not comparable, so it will never use tree based bins. 

A sensible way to compare byte arrays is needed before this test is enabled. I'll create a separate JIRA for this. It's a potentially suboptimal thing, but nothing really critical (i.e. out previous keys, i.e. ByteArrayKey, was not comparable either).