Reading `addTokenForUser(String, Token, long)`, it seems like we don't _need_ to have a lifetime, which matches the warning (not failure) here. Lazy question: do we have an "expectation" on how it should work? Like, does Knox always give us a lifetime? What about the nimbus test server?    If the jwt server doesn't give us a lifetime, do we have any kind of loss of functionality on the HBase client side?