old_contents: # Obligatory set up code
  import vtki
  from vtki import examples
  import numpy as np
  # Set a document-friendly plotting theme
  vtki.set_plot_theme('document')
  
  # Example mesh of Queen Nefertiti
  mesh = examples.download_nefertiti()
  # Render the dataset
  mesh.plot(cpos=[-1,-1,0.2], eye_dome_lighting=True,
            screenshot='nefertiti.png')
  
  # Load an example uniform grid
  dataset = examples.load_uniform()
  # Apply a threshold over a data range
  threshed = dataset.threshold([100, 500]) # Figure 4 A
  
  outline = dataset.outline()
  contours = dataset.contour() # Figure 4 B
  slices = dataset.slice_orthogonal() # Figure 4 C
  glyphs = dataset.glyph(factor=1e-3, geom=vtki.Sphere()) # Figure 4 D
  
  # Two by two comparison
  vtki.plot_compare_four(threshed, contours, slices, glyphs,
                          {'show_scalar_bar':False},
                          camera_position=[-2,5,3], outline=outline,
                          screenshot='filters.png')
  
  # Apply a filtering chain
  result = dataset.threshold([100, 500], invert=True).elevation().clip(normal='z').slice_orthogonal()
  
new_contents: # Obligatory set up code
  import vtki
  from vtki import examples
  import numpy as np
  # Set a document-friendly plotting theme
  vtki.set_plot_theme('document')
  
  # Load an example uniform grid
  dataset = examples.load_uniform()
  # Apply a threshold over a data range
  threshed = dataset.threshold([100, 500]) # Figure 4 A
  
  outline = dataset.outline()
  contours = dataset.contour() # Figure 4 B
  slices = dataset.slice_orthogonal() # Figure 4 C
  glyphs = dataset.glyph(factor=1e-3, geom=vtki.Sphere()) # Figure 4 D
  
  # Two by two comparison
  vtki.plot_compare_four(threshed, contours, slices, glyphs,
                          {'show_scalar_bar':False},
                          # {'border':False},
                          camera_position=[-2,5,3], outline=outline,
                          screenshot='filters.png')
  
  # Apply a filtering chain
  result = dataset.threshold([100, 500], invert=True).elevation().clip(normal='z').slice_orthogonal()
  
subject: Update JOSS code example file