code: def test_brevity_penalty_default():
      hyp_lengths = pt.tensor([[1], [2], [3]])
      ref_lengths = pt.tensor([[2], [3], [2]])
      brevity_penalty = sockeye.beam_search.BrevityPenalty(0.0)
      expected_bp = pt.tensor([[0], [0], [0]], dtype=pt.long)
      pt.testing.assert_close(
          brevity_penalty(hyp_lengths, ref_lengths), expected_bp
      )
  
imports: from typing import List, Optional
  from typing import Tuple
  import numpy
  import pytest
  import torch
  import numpy
  import sockeye.beam_search
  import sockeye.constants
  import sockeye.lexicon
  import sockeye.utils
label_desc: Use image node_id 4 for calling a global function with example usage: test_brevity_penalty_default() without return types