@Override
    public RequestCallback filter(Method method, Response response, RequestCallback callback) {
        int code = response.getStatusCode();

        final CacheKey ck = cacheKey(method.builder);
        final List<RequestCallback> removedCallbacks = cache.removeCallbacks(ck);

        if (removedCallbacks != null) {
            callback = new RequestCallback() {
                @Override
                public void onResponseReceived(Request request, Response response) {
                    if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName())
                            .finer("call " + removedCallbacks.size() + " more queued callbacks for " + ck);
                    }

                    // call all callbacks found in cache
                    for (RequestCallback cb : removedCallbacks) {
                        cb.onResponseReceived(request, response);
                    }
                }

                @Override
                public void onError(Request request, Throwable exception) {
                    if (LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName()).severe(
                            "cannot call " + (removedCallbacks.size() + 1) + " callbacks for " + ck +
                                " due to error: " + exception.getMessage());
                    }

                    if (LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName())
                            .finer("call " + removedCallbacks.size() + " more queued callbacks for " + ck);
                    }

                    // and all the others, found in cache
                    for (RequestCallback cb : removedCallbacks) {
                        cb.onError(request, exception);
                    }
                }
            };
        } else {
            if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
                Logger.getLogger(CachingCallbackFilter.class.getName())
                    .finer("removed one or no " + "callback for cachekey " + ck);
            }
        }

        if (isCachingStatusCode(code)) {
            cacheResult(method, response);
            return callback;
        }

        if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
            Logger.getLogger(CachingCallbackFilter.class.getName())
                .info("cannot cache due to invalid response code: " + code);
        }
        return callback;
    }
@Override
    public RequestCallback filter(Method method, Response response, RequestCallback callback) {
        int code = response.getStatusCode();

        final CacheKey ck = cacheKey(method.builder);
        final List<RequestCallback> removedCallbacks = cache.removeCallbacks(ck);

        if (removedCallbacks != null) {
            callback = new RequestCallback() {
                @Override
                public void onResponseReceived(Request request, Response response) {
                    if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName())
                            .finer("call " + removedCallbacks.size() + " more queued callbacks for " + ck);
                    }

                    
                    for (RequestCallback cb : removedCallbacks) {
                        cb.onResponseReceived(request, response);
                    }
                }

                @Override
                public void onError(Request request, Throwable exception) {
                    if (LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName()).severe(
                            "cannot call " + (removedCallbacks.size() + 1) + " callbacks for " + ck +
                                " due to error: " + exception.getMessage());
                    }

                    if (LogConfiguration.loggingIsEnabled()) {
                        Logger.getLogger(CachingCallbackFilter.class.getName())
                            .finer("call " + removedCallbacks.size() + " more queued callbacks for " + ck);
                    }

                    
                    for (RequestCallback cb : removedCallbacks) {
                        cb.onError(request, exception);
                    }
                }
            };
        } else {
            if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
                Logger.getLogger(CachingCallbackFilter.class.getName())
                    .finer("removed one or no " + "callback for cachekey " + ck);
            }
        }

        if (isCachingStatusCode(code)) {
            cacheResult(method, response);
            return callback;
        }

        if (GWT.isClient() && LogConfiguration.loggingIsEnabled()) {
            Logger.getLogger(CachingCallbackFilter.class.getName())
                .info("cannot cache due to invalid response code: " + code);
        }
        return callback;
    }
@ Override public RequestCallback filter ( Method method , Response response , RequestCallback callback ) { int code = response . getStatusCode ( ) ; final CacheKey ck = cacheKey ( method . builder ) ; final List < RequestCallback > removedCallbacks = cache . removeCallbacks ( ck ) ; if ( removedCallbacks != null ) { callback = new RequestCallback ( ) { @ Override public void onResponseReceived ( Request request , Response response ) { if ( GWT . isClient ( ) && LogConfiguration . loggingIsEnabled ( ) ) { Logger . getLogger ( CachingCallbackFilter . class . getName ( ) ) . finer ( "call " + removedCallbacks . size ( ) + " more queued callbacks for " + ck ) ; } // call all callbacks found in cache for ( RequestCallback cb : removedCallbacks ) { cb . onResponseReceived ( request , response ) ; } } @ Override public void onError ( Request request , Throwable exception ) { if ( LogConfiguration . loggingIsEnabled ( ) ) { Logger . getLogger ( CachingCallbackFilter . class . getName ( ) ) . severe ( "cannot call " + ( removedCallbacks . size ( ) + 1 ) + " callbacks for " + ck + " due to error: " + exception . getMessage ( ) ) ; } if ( LogConfiguration . loggingIsEnabled ( ) ) { Logger . getLogger ( CachingCallbackFilter . class . getName ( ) ) . finer ( "call " + removedCallbacks . size ( ) + " more queued callbacks for " + ck ) ; } // and all the others, found in cache for ( RequestCallback cb : removedCallbacks ) { cb . onError ( request , exception ) ; } } } ; } else { if ( GWT . isClient ( ) && LogConfiguration . loggingIsEnabled ( ) ) { Logger . getLogger ( CachingCallbackFilter . class . getName ( ) ) . finer ( "removed one or no " + "callback for cachekey " + ck ) ; } } if ( isCachingStatusCode ( code ) ) { cacheResult ( method , response ) ; return callback ; } if ( GWT . isClient ( ) && LogConfiguration . loggingIsEnabled ( ) ) { Logger . getLogger ( CachingCallbackFilter . class . getName ( ) ) . info ( "cannot cache due to invalid response code: " + code ) ; } return callback ; }
the real filter method, called independent of the response code

TODO method.getResponse() is not equal to response. unfortunately
the real filter method called independent of the response code