old_contents: #!/usr/bin/env python
  
  import os
  
  # This is failing for now on Windows. We need to submit
  # a patch to the graphviz package to fix it
  if not os.name == 'nt':
      # Install graphviz Python package
      import pip
      pip.main(['install', 'graphviz'])
  
      # Dask test
      import dask.array as da
      x = da.ones(4, chunks=(2,))
      for fmt in ['pdf', 'png', 'dot', 'svg']:
          (x + 1).sum().visualize(filename='graph.%s' % fmt)
  
new_contents: #!/usr/bin/env python
  
  import os
  
  # This is failing for now on Windows. We need to submit
  # a patch to the Python graphviz package to fix it
  if not os.name == 'nt':
      # Install graphviz Python package
      import pip
      pip.main(['install', 'graphviz'])
  
      # Dask test
      import dask.array as da
      x = da.ones(4, chunks=(2,))
      for fmt in ['pdf', 'png', 'dot', 'svg']:
          (x + 1).sum().visualize(filename='graph.%s' % fmt)
  
subject: Improve a comment