KeepAlive

TODO: fill this section

The state machine for the KeepAlive protocol is as follows:

stateDiagram
  direction LR
  [*] --> StClient
  StClient --> StServer: MsgKeepAlive
  StServer --> StClient: MsgKeepAliveResponse
  StClient --> StDone: MsgDone

The CDDL for the messages in KeepAlive is as follows:

;; messages.cddl
keepAliveMessage = msgKeepAlive
                 / msgKeepAliveResponse
                 / msgDone

msgKeepAlive = [ 0, base.word16 ]
msgKeepAliveResponse = [ 1, base.word16 ]
msgDone = [ 2 ]

;# import base as base