* Over head is quite small, at just 225 bytes if assuming 5 hops
* Most likely also don’t even need the message at all?
* What would it contain?
* Bunch of TODO’s still left in the code, need to write the portion for
processing and forwarding mix headers received by the nodes.
* After the processing stuff, need to write an extensive set of tests
to ensure correctness.
* Also, need to figure out the division between nodeID and lightning
address. For sphinx, they must be “prefix free”.