old_contents: from collections import OrderedDict
  
  
  keys = OrderedDict([
      ("j", "down"),
      ("k", "up"),
      ("ctrl f", "page down"),
      ("ctrl b", "page up")]
  )
  
new_contents: from collections import OrderedDict
  
  
  keys = OrderedDict([
      ("j", "down"),
      ("k", "up"),
      ("ctrl f", "page down"),
      ("ctrl d", "page down"),
      ("ctrl b", "page up"),
      ("ctrl u", "page up")]
  )
  
subject: Add ctrl+d/ctrl+u for page down and page up