text: from __future__ import print_function
  
  import webbrowser
  
  import neuroglancer
  
  viewer = neuroglancer.Viewer()
  with viewer.txn() as s:
      s.layers['image'] = neuroglancer.ImageLayer(
          source='brainmaps://1016859101264:janelia-flyem-cx:raw',
      )
  
  def my_action(s):
      print('Got my-action')
      print('  Mouse position: %s' % (s.mouse_voxel_coordinates,))
      print('  Layer selected values: %s' % (s.selected_values,))
  viewer.actions.add('my-action', my_action)
  with viewer.config_state.txn() as s:
      s.input_event_bindings.viewer['keyt'] = 'my-action'
      s.status_messages['hello'] = 'Welcome to this example'
  
  print(viewer)
  webbrowser.open_new(viewer.get_viewer_url())
  