new_contents: """
  Extension for disabling autoscrolling long output, which is super annoying sometimes
  
  Usage:
  
      %load_ext disable_autoscroll
  
  You can also put the js snippet below in profile_dir/static/js/custom.js
  """
  
  from IPython.display import display, Javascript
  
  disable_js = """
  IPython.OutputArea.prototype._should_scroll = function(lines) {
      return false;
  }
  """
  
  def load_ipython_extension(ip):
      display(Javascript(disable_js))
      print ("autoscrolling long output is disabled")
  
subject: add disable_autoscroll extension