code: def l1_dist(a, b):
      return sum(abs(ai - bi) for ai, bi in zip(a, b))
  
file_path: river/river/multiclass/occ.py
imports: from __future__ import annotations
  import collections
  import random
  from river import base, linear_model
label_desc: Use image node_id 1 for calling a global function with example usage: l1_dist(a, b) and returns: sum