class_docstr: GPT Loss
class_docstr_tok: ["GPT","Loss"]
code: def __init__(self):
      super().__init__()
      self.loss_fn = nn.CrossEntropyLoss()
  
imports: import time
  from copy import deepcopy
  from typing import Callable, Tuple
  import numpy
  import torch
  import torch.nn
  from transformers import GPT2Config, GPT2LMHeadModel
  from colossalai.auto_parallel.checkpoint import CheckpointSolverRotor
  from colossalai.fx import metainfo_trace
label_desc: Use image node_id 1 to create a new GPTLMLoss object from inherited base classes: nn with example: obj = GPTLMLoss()