code: def download_model(model_name):
      """
      Downloads a pre-trained DiT model from the web.
      """
      local_path = f"pretrained_models/{model_name}"
      if not os.path.isfile(local_path):
          os.makedirs("pretrained_models", exist_ok=True)
          web_path = (
              f"https://dl.fbaipublicfiles.com/DiT/models/{model_name}"
          )
          download_url(web_path, "pretrained_models")
      model = torch.load(
          local_path, map_location=lambda storage, loc: storage
      )
      return model
  
imports: import argparse
  import os
  import torch
  from torchvision.datasets.utils import download_url
  from diffusers import AutoencoderKL, DDIMScheduler, DiTPipeline, Transformer2DModel
label_desc: Use image node_id 1 for calling a global function with example usage: download_model(model_name) and returns: model