anchor.diff:  
   parse_results(Result, RegId, ErrorFun) ->
       case {
  -        proplists:get_value(<<"error">>, Result),
  -        proplists:get_value(<<"message_id">>, Result),
  -        proplists:get_value(<<"registration_id">>, Result)
  -    } of
  +      proplists:get_value(<<"error">>, Result),
  +      proplists:get_value(<<"message_id">>, Result),
  +      proplists:get_value(<<"registration_id">>, Result)
  +     } of
           {Error, undefined, undefined} when Error =/= undefined ->
               ErrorFun(Error, RegId);
           {undefined, MessageId, undefined} when MessageId =/= undefined ->
  
positive.code: 
  get_response_fields(Json) ->
      {
          proplists:get_value(<<"multicast_id">>, Json),
          proplists:get_value(<<"success">>, Json),
          proplists:get_value(<<"failure">>, Json),
          proplists:get_value(<<"canonical_ids">>, Json),
          proplists:get_value(<<"results">>, Json)
      }.
  
  to_be_parsed(0, 0) -> false;
  
negative.code:     error_logger:info_msg("Message=~p; RegIds=~p~n", [Message, RegIds]),
      Request = jsx:encode([{<<"registration_ids">>, RegIds}|Message]),
      ApiKey = string:concat("key=", Key),
      
      try httpc:request(post, {?BASEURL, [{"Authorization", ApiKey}], "application/json", Request}, [], []) of
          {ok, {{_, 200, _}, _Headers, Body}} ->
              Json = jsx:decode(response_to_binary(Body)),
  