class_docstr: Test that build_transform is able to build torch losses correctly.
docstr: Test CrossEntropyLoss
docstr_tok: ["Test","CrossEntropyLoss"]
code: def test_cross_entropy_loss(self):
      """
      Test CrossEntropyLoss
      """
      config = {
          "name": "CrossEntropyLoss",
          "weight": [1.0, 1.0],
          "ignore_index": -1,
          "reduction": "mean",
      }
      output = torch.tensor([[9.0, 1.0]])
      target = torch.tensor([1])
      expected_loss = 8.000335693359375
      self._test_loss(config, output, target, expected_loss)
  
file_path: ClassyVision/test/losses_test.py
imports: import unittest
  import torch
  from classy_vision.generic.util import get_torch_version
  from classy_vision.losses import build_loss
label_desc: Use image node_id 2 for calling the CriterionsTest obj's underlying member method code with example usage: obj.test_cross_entropy_loss() without return types