old_contents: import numpy as np
  import bluesky.callbacks
  import matplotlib.pyplot as plt
  from cycler import cycler
  
  xct = 10
  yct = 15
  ict = xct * yct
  
  cb = bluesky.callbacks.LiveRaster((yct, xct),  'I', clim=[0, 1])
  
  cb('start', {})
  cy = ((cycler('x', np.linspace(0, 1, xct, endpoint=True)) *
         cycler('y', np.linspace(0, 1, yct, endpoint=True))) +
        cycler('I', np.linspace(0, 1, ict, endpoint=True)))
  for j, d in enumerate(cy):
      ev = {'data': d, 'seq_num': j + 1}
      cb('event', ev)
      plt.pause(.1)
  
new_contents: import numpy as np
  import bluesky.callbacks
  import matplotlib.pyplot as plt
  from cycler import cycler
  import uuid
  
  xct = 10
  yct = 15
  ict = xct * yct
  
  cb = bluesky.callbacks.LiveRaster((yct, xct),  'I', clim=[0, 1],
                                    aspect='auto')
  
  cb('start', {'scan_id': 1, 'uid': str(uuid.uuid4())})
  cy = ((cycler('x', np.linspace(0, 1, xct, endpoint=True)) *
         cycler('y', np.linspace(0, 1, yct, endpoint=True))) +
        cycler('I', np.linspace(0, 1, ict, endpoint=True)))
  for j, d in enumerate(cy):
      ev = {'data': d, 'seq_num': j + 1}
      cb('event', ev)
      plt.pause(.1)
  
subject: update example