code: def plot_compare_four(data_a, data_b, data_c, data_d, disply_kwargs=None,
                        plotter_kwargs=None, show_kwargs=None, screenshot=None,
                        camera_position=None, outline=None, outline_color='k',
                        labels=('A', 'B', 'C', 'D')):
      
      datasets = [[data_a, data_b], [data_c, data_d]]
      labels = [labels[0:2], labels[2:4]]
  
      if plotter_kwargs is None:
          plotter_kwargs = {}
      if disply_kwargs is None:
          disply_kwargs = {}
      if show_kwargs is None:
          show_kwargs = {}
  
      p = vtki.Plotter(shape=(2,2), **plotter_kwargs)
  
      for i in range(2):
          for j in range(2):
              p.subplot(i, j)
              p.add_mesh(datasets[i][j], **disply_kwargs)
              p.add_text(labels[i][j])
              if is_vtki_obj(outline):
                  p.add_mesh(outline, color=outline_color)
              if camera_position is not None:
                  p.camera_position = camera_position
  
      return p.show(screenshot=screenshot, **show_kwargs)
docs: Plot a 2 by 2 comparison of data objects. Plotting parameters and camera
      positions will all be the same.