code: def get_mpl_heatmap_axes(dfr, fig, heatmap_gs):
      
      # Create heatmap axis
      heatmap_axes = fig.add_subplot(heatmap_gs[1, 1])
      heatmap_axes.set_xticks(np.linspace(0, dfr.shape[0] - 1, dfr.shape[0]))
      heatmap_axes.set_yticks(np.linspace(0, dfr.shape[0] - 1, dfr.shape[0]))
      heatmap_axes.grid(False)
      heatmap_axes.xaxis.tick_bottom()
      heatmap_axes.yaxis.tick_right()
      return heatmap_axes
docs: Return axis for Matplotlib heatmap.