anchor.diff:  %% {@link node_manager_plugin_behaviour}  callback on_init/0.
   %% @end
   %%--------------------------------------------------------------------
  --spec on_init(Args :: term()) -> Result when
  -  Result :: {ok, State}
  -  | {ok, State, Timeout}
  -  | {ok, State, hibernate}
  -  | {stop, Reason :: term()}
  -  | ignore,
  -  State :: term(),
  -  Timeout :: non_neg_integer() | infinity.
  +-spec on_init(Args :: term()) -> Result :: ok | {error, Reason :: term()}.
   on_init([]) ->
     try
       ensure_correct_hostname(),
  
positive.code: %% List ccm nodes to be used by node manager.
  %% @end
  %%--------------------------------------------------------------------
  -spec ccm_nodes() -> Nodes :: [atom()].
  ccm_nodes() ->
    application:get_env(?APP_NAME, ccm_nodes).
  
  
negative.code: %% List db nodes to be used by node manager.
  %% @end
  %%--------------------------------------------------------------------
  -spec db_nodes() -> {ok, Nodes :: [atom()]} | undefined.
  db_nodes() ->
    application:get_env(?APP_NAME, db_nodes).
  
  