anchor.diff:          {_RedisUrl, Pid} -> Pid;
           Other -> exit({shard_not_found, Other})
       end.
  +
  +urls() ->
  +    gen_server:call(?MODULE, urls).
   
   %%====================================================================
   %% gen_server callbacks
  
positive.code: %% Description: Handling call messages
  %% @hidden
  %%--------------------------------------------------------------------
  handle_call(_Msg, _From, State) ->
      {reply, {error, invalid_call}, State}.
  
  
negative.code: -export([start_link/0, init/1, handle_call/3, handle_cast/2, 
  	     handle_info/2, terminate/2, code_change/3]).
  
  -export([lookup/3, lookup_urls/0, urls/0, list_diff/2, poll_shard_urls/0]).
  
  -include_lib("logplex.hrl").
  
  