anchor.diff:      CommitRes.
   
   %% @doc Unsubscribes a URL from a topic.
  --spec unsubscribe(string(), string()) -> api_tx:commit_result() | {fail, not_found}.
  +-spec unsubscribe(client_key(), string()) -> api_tx:commit_result() | {fail, not_found}.
   unsubscribe(Topic, URL) ->
       {TLog, Res} = api_tx:read(api_tx:new_tlog(), Topic),
       case Res of
  
positive.code:     end.
  
  %% @doc Queries the subscribers of a query.
  -spec get_subscribers(Topic::string()) -> [string()].
  get_subscribers(Topic) ->
      {Res, Value} = api_tx:read(Topic),
      case Res of
  
negative.code: 
  -export([publish/2, subscribe/2, unsubscribe/2, get_subscribers/1]).
  
  -include("client_types.hrl").
  
  %% @doc Publishes an event under a given topic.
  -spec publish(client_key(), string()) -> {ok}.
  publish(Topic, Content) ->
      Subscribers = get_subscribers(Topic),
      _ = [ pubsub_publish:publish(X, Topic, Content) || X <- Subscribers ],
      {ok}.
  
  %% @doc Subscribes a URL for a topic.
  -spec subscribe(client_key(), string()) -> api_tx:commit_result().
  subscribe(Topic, URL) ->
      {TLog, Res} = api_tx:read(api_tx:new_tlog(), Topic),
      {_TLog2, [_, CommitRes]} =
  