code: def test_mst_finds_maximum_spanning_tree(self):
      energy = torch.range(1, 9).view(1, 3, 3)
      heads, _ = decode_mst(
          energy.numpy(), 3
      )  # pylint: disable=protected-access
      assert list(heads) == [-1, 2, 0]
  
file_path: magnitude/pymagnitude/third_party/allennlp/tests/nn/decoding/chu_liu_edmonds_test.py
imports: from __future__ import with_statement
  from __future__ import absolute_import
  import numpy
  import pytest
  import torch
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.common.checks import ConfigurationError
  from allennlp.nn.decoding.chu_liu_edmonds import _find_cycle, decode_mst
label_desc: Use image node_id 3 for calling the ChuLiuEdmondsTest obj's underlying member method code with example usage: obj.test_mst_finds_maximum_spanning_tree() without return types