anchor.diff:  handle_call(stop, _From, State) ->
       {stop, normal, stopped, State};
   
  -handle_call({send, RegIds, Message}, _From, #state{key=Key} = State) ->
  -    Reply = do_push(RegIds, Message, Key),
  +handle_call({send, RegIds, Message, Retry}, _From, #state{key=Key} = State) ->
  +    Reply = do_push(RegIds, Message, Key, Retry),
       {reply, Reply, State};
   
   handle_call(_Request, _From, State) ->
       Reply = ok,
       {reply, Reply, State}.
   
  -handle_cast({send, RegIds, Message}, #state{key=Key} = State) ->
  -    do_push(RegIds, Message, Key),
  +handle_cast({send, RegIds, Message, Retry}, #state{key=Key} = State) ->
  +    do_push(RegIds, Message, Key, Retry),
       {noreply, State};
   
   handle_cast(_Msg, State) ->
  
positive.code:     {_MulticastId, _SuccessesNumber, _FailuresNumber, _CanonicalIdsNumber, Results} = GCMResult,
      lists:map(fun({Result, RegId}) -> {RegId, parse(Result)} end, lists:zip(Results, RegIds)).
  
  do_backoff(RetryAfter, RegIds, Message, Key) ->
      case RetryAfter of
          no_retry ->
              ok;
  	_ ->
  	    timer:apply_after(RetryAfter * 1000, ?MODULE, do_push, [RegIds, Message, Key])
      end.
  
  parse(Result) ->
  
negative.code:     {ok, State}.
  
  %% Internal
  do_push(RegIds, Message, Key, Retry) ->
      error_logger:info_msg("Sending message: ~p to reg ids: ~p. Retry number: ~p~n", [Message, RegIds, Retry]),
      case gcm_api:push(RegIds, Message, Key) of
          {ok, GCMResult} ->
              handle_result(GCMResult, RegIds);
          {error, {retry, RetryAfter}} ->
              do_backoff(RetryAfter, RegIds, Message, Key, Retry),
              {error, retry};
          {error, Reason} ->
              {error, Reason}
  