code: def main(unused_argv):
      print("Saving output to %s." % LOGDIR)
      run(LOGDIR)
      print("Done. Output saved to %s." % LOGDIR)
  
file_path: tensorboard/tensorboard/plugins/custom_scalar/custom_scalar_demo.py
imports: from absl import app
  import tensorflow
  from tensorboard.plugins.custom_scalar import summary
  from tensorboard.plugins.custom_scalar import layout_pb2
label_desc: Use image node_id 4 for calling a global function with example usage: main(unused_argv) without return types