@Override
                    public void endHandler(IAsyncHandler<Void> endHandler) {
                        this.endHandler = endHandler;
                    }
@see io.apiman.gateway.engine.components.ICacheStoreComponent#getBinary(java.lang.String, java.lang.Class, io.apiman.gateway.engine.async.IAsyncResultHandler)
gateway/engine/es/src/main/java/io/apiman/gateway/engine/es/EsCacheStoreComponent.java