code: def forward(
      self,
      seq_group_meta_data_lists: List[SequenceGroupMetadata],
      kv_cache: Optional = None,
      input_metadata: Optional = None,
  ) -> Tuple[torch.Tensor, List[Tuple[torch.Tensor, torch.Tensor]]]:
      pass
  
imports: import torch
  from torch import nn
  from typing import Optional, Tuple, List, Type, Dict
  from transformers import LlamaConfig
  from bigdl.llm.vllm.sequence import SequenceOutputs, SequenceGroupMetadata
  from bigdl.llm.transformers.models.utils import extend_kv_cache
  from bigdl.llm.vllm.logger import init_logger
label_desc: Use image node_id 9 for calling the BigDLModelForCausalLM obj's underlying member method code with example usage: obj.forward(seq_group_meta_data_lists, kv_cache, input_metadata) without return types