code: def _plot_weights_heatmap(self, index=None, figsize=None, **kwargs):
          
          W = self.get_weights()[0]
          if index is None:
              index = np.arange(W.shape[2])
  
          fig = heatmap(np.swapaxes(W[:, :, index], 0, 1), plot_name="filter: ",
                        vocab=self.VOCAB, figsize=figsize, **kwargs)
          # plt.show()
          return fig
docs: Plot weights as a heatmap
  
          index = can be a particular index or a list of indicies
          **kwargs - additional arguments to concise.utils.plot.heatmap