code: def main(argv: Sequence[str]) -> Optional[dev_server.LitServerType]:
      if len(argv) > 1:
          raise app.UsageError("Too many command-line arguments.")
  
      # Load our trained model.
      model = _MODEL.value
      if model.endswith(".tar.gz"):
          model = file_cache.cached_path(
              model, extract_compressed_file=True
          )
  
      models = {"sst": glue_models.SST2Model(model)}
      datasets = {"sst_dev": glue.SST2Data("validation")}
  
      # Start the LIT server. See server_flags.py for server options.
      lit_demo = dev_server.Server(
          models,
          datasets,
          layouts={"potato": POTATO_LAYOUT},
          **server_flags.get_flags(),
      )
      return lit_demo.serve()
  
file_path: lit/lit_nlp/examples/custom_module/potato_demo.py
imports: from collections.abc import Sequence
  import os
  import pathlib
  import sys
  from typing import Optional
  from absl import app
  from absl import flags
  from absl import logging
  from lit_nlp import dev_server
  from lit_nlp import server_flags
  from lit_nlp.api import layout
  from lit_nlp.examples.datasets import glue
  from lit_nlp.examples.models import glue_models
  from lit_nlp.lib import file_cache
label_desc: Use image node_id 2 for calling a global function with example usage: main(argv) and returns: lit_demo