Hmm. I hadn't noticed it before, but it's peculiar that a byte array (byte[]) is used as a key for a map. Usually arrays are a poor choice as map keys as arrays only provide strict/shallow equality (meaning the reference has to be identical to have a match). In other words, if you have two different arrays with the same content, they will be different keys although the contents match.

So the only way byte arrays can work as map keys is if you're dealing with well-known fixed (or constant) byte arrays as keys. Is that the case here?