anchor.diff:  start_link(NodeRef, NodeAddr) ->
       gen_fsm:start_link(?MODULE, [NodeRef, NodeAddr], []).
   
  -heartbeat(NodeRef) ->
  -    send_info(NodeRef, heartbeat),
  -    ok.
   recv_msg(Message) ->
       dispatch_raw_message(Message).
   
  
positive.code:          recv_msg/1,
           send_msg/2,
           send_msg/3,
           heartbeat/1,
           status/1,
           watch/1,
           aborted/1,
           rehab/1]).
  
  %% States
  -export([idle/2,
           post_init/2,
           running/2,
           rehab/2]).
  
  -record(state, {node_ref              :: node_ref(),
  
negative.code: eval_state({post_init, undefined}) ->
      {online, {unavailable, none}};
  eval_state({rehab, undefined}) ->
      {online, {unavailable, none}}.
  
  rehab_interval() ->
      envy:get(pushy, rehab_timer, 1000, integer).
  