new_contents: from spinn import util
  
  NUMBERS = range(-10, 11)
  
  FIXED_VOCABULARY = {str(x): i + 1 for i, x in enumerate(NUMBERS)}
  FIXED_VOCABULARY.update({
      util.PADDING_TOKEN: 0,
      "+": len(FIXED_VOCABULARY) + 1,
      "-": len(FIXED_VOCABULARY) + 2
  })
  assert len(set(FIXED_VOCABULARY.values())) == len(FIXED_VOCABULARY.values())
  
subject: Add missing base file.