code: @Override
      public long numParams(boolean backwards) {
          int length = 0;
          for (int i = 0; i < layers.length; i++)
              length += layers[i].numParams(backwards);
  
          return length;
      }
docs: Returns the number of parameters in the network
  
  @param  backwards If true: exclude any parameters uned only in unsupervised layerwise training (such as the decoder
  parameters in an autoencoder)
  @return The number of parameters