anchor.diff:  start_link(Opts) ->
       gen_server:start_link({local, ?MODULE}, ?MODULE, Opts, []).
   
  +%% @doc Mark a task as completed.
  +-spec task_completed(atom(), atom()) -> ok.
  +task_completed(Task, Node) ->
  +    gen_server:call(?MODULE, {task_completed, Task, Node}, infinity).
  +
   %%%===================================================================
   %%% gen_server callbacks
   %%%===================================================================
  
positive.code:     Result = eredis:start_link(RedisHost, list_to_integer(RedisPort)),
      Eredis = case Result of
          {ok, C} ->
              C;
          {error, Error} ->
              lager:error("Error connecting to redis for workflow management: ~p",
                          [Error]),
  
negative.code: 
  %% API
  -export([start_link/0,
           start_link/1,
           task_completed/2]).
  
  %% gen_server callbacks
  -export([init/1,
  