old_contents: '''
  Demo script for demonstrating the imshow() function
  '''
  
  import matplotlib.pyplot as plt
  import matplotlib.cm as cm
  
  x = [[0, 0, 0],
       [0, 0, 0],
       [0, 0, 1]]
  plt.imshow(x, cmap=cm.Greys_r)
  plt.show()
  
new_contents: '''
  Demo script for demonstrating the imshow() function
  '''
  
  import matplotlib.pyplot as plt
  import matplotlib.cm as cm
  
  x = [[0, 0, 0],
       [0, 0, 0],
       [0, 0, 1]]
  plt.imshow(x, cmap=cm.gray)
  plt.show()
  
subject: use cm.gray