code: def acc_difference(points):
      
      data = [0]
      for before, after in pairwise(points):
          data.append(before.acc - after.acc)
      return data
docs: Computes the accelaration difference between each adjacent point
  
      Args:
          points (:obj:`Point`)
      Returns:
          :obj:`list` of int: Indexes of changepoints