code: def bhattacharyya(h1, h2):
      return 1 - sum(math.sqrt(hi * hj) for hi, hj in zip(h1, h2))
  
imports: from __future__ import annotations
  import math
  import random
  import pytest
  import dask.bag
  from dask.bag import random
label_desc: Use image node_id 19 for calling a global function with example usage: bhattacharyya(h1, h2) and returns: unknown