for (int i = 0; i < decoderLayerSizes.length; i++) {
            String w = "d" + i + VariationalAutoencoderParamInitializer.WEIGHT_KEY_SUFFIX;
            g.put(w, gradientMap.get(w));
            String b = "d" + i + VariationalAutoencoderParamInitializer.BIAS_KEY_SUFFIX;
            g.put(b, gradientMap.get(b));