code: def __init__(self, weight=None, size_average=True, ignore_index=255):
      super(CrossEntropyLoss2d, self).__init__()
      self.nll_loss = nn.NLLLoss2d(weight, size_average, ignore_index)
  
imports: import os
  from math import ceil
  import numpy
  import torch
  import torch.nn.functional
  from torch import nn
label_desc: Use image node_id 1 to create a new CrossEntropyLoss2d object from inherited base classes: nn with example: obj = CrossEntropyLoss2d(weight, size_average, ignore_index)