anchor.diff:      gen_server:call(Pool, {checkout, Timeout}).
   
   checkin(Pool, Worker) ->
  -    gen_server:call(Pool, {checkin, Worker}).
  +    gen_server:cast(Pool, {checkin, Worker}).
   
   transaction(Pool, Transaction) ->
       gen_server:call(Pool, {transaction, Transaction}).
  
positive.code:     Args = proplists:get_value(<<"args">>, Descriptor),
      case jesse:validate_with_schema(jsonx:decode(Schema), Args) of
          {ok, _Args} ->
              %% NOTE TCP connetor is used to listen on the hive side. It's assumed to be fine.
              ok;
  
          {error, Error} ->
  
negative.code:             {reply, {error, Error}, State}
      end;
  
  handle_call({transaction, Transaction}, From, State) ->
      case checkout_worker(State) of
          retry_later ->
  