code: def main(argv):
      assert (
          len(argv) == 1
      ), "Please specify arguments via flags. Use --help for instructions"
  
      assert not os.path.exists(
          FLAGS.output_dir
      ), "Output directory already exists. Delete manually or specify a new one."
      os.makedirs(FLAGS.output_dir)
  
      ds = Dataset(FLAGS.dataset)
      loader = elegy.data.DataLoader(
          ds,
          batch_size=FLAGS.batch_size,
          n_workers=os.cpu_count(),
          worker_type="process",
      )
  
      wgan = WGAN_GP()
      wgan.init(np.zeros([8, 128]))
  
      wgan.fit(
          loader,
          epochs=FLAGS.epochs,
          verbose=4,
          callbacks=[
              SaveImagesCallback(wgan, FLAGS.output_dir),
              elegy.callbacks.ModelCheckpoint(FLAGS.output_dir),
          ],
      )
  
file_path: elegy/examples/need-fixing/WGAN-GP/main.py
imports: import glob
  import os
  import pickle
  import numpy
  import PIL.Image
  from absl import app, flags
  from model import WGAN_GP
  import elegy
label_desc: Use image node_id 1 for calling a global function with example usage: main(argv) without return types