code: def forward(self, input_ids, attention_mask):
      # Only return lm_logits
      return self.model(
          input_ids=input_ids,
          attention_mask=attention_mask,
          use_cache=not self.checkpoint,
      )[0]
  
file_path: ColossalAI/examples/language/gpt/experiments/pipeline_parallel/model_zoo.py
imports: from torch import nn
  from transformers import GPT2Config, GPT2LMHeadModel
label_desc: Use image node_id 2 for calling the GPTLMModel obj's underlying member method code with example usage: obj.forward(input_ids, attention_mask) and returns: self