code: def _init_first_stage(self, config):
      model = instantiate_from_config(config).eval()
      model.train = disabled_train
      for param in model.parameters():
          param.requires_grad = False
      self.first_stage_model = model
  
imports: import math
  from contextlib import contextmanager
  from typing import Any, Dict, List, Optional, Tuple, Union
  import pytorch_lightning
  import torch
  from omegaconf import ListConfig, OmegaConf
  from safetensors.torch import load_file
  from torch.optim.lr_scheduler import LambdaLR
  from ..modules import UNCONDITIONAL_CONFIG
  from ..modules.autoencoding.temporal_ae import VideoDecoder
  from ..modules.diffusionmodules.wrappers import OPENAIUNETWRAPPER
  from ..modules.ema import LitEma
  from ..util import default, disabled_train, get_obj_from_str, instantiate_from_config, log_txt_as_img
label_desc: Use image node_id 3 for calling the DiffusionEngine obj's underlying member method code with example usage: obj._init_first_stage(config) without return types