code: def test_bce_raises_by_default(self):
      assertion = lambda fn, x: self.assertRaises(
          NotImplementedError, fn, x
      )
      self.bce_common(assertion)
  
imports: import unittest
  import functools
  import itertools
  from apex import amp
  import torch
  from torch import nn
  import torch.nn.functional
  from utils import common_init, HALF, FLOAT, ALWAYS_HALF, ALWAYS_FLOAT, MATCH_INPUT
label_desc: Use image node_id 4 for calling the TestBannedMethods obj's underlying member method code with example usage: obj.test_bce_raises_by_default() without return types