code: def test_deck_layer_args():
      """Verify layer argument null cases"""
      CASES = [({"layers": None}, []), ({"layers": []}, [])]
      for [args, expected_output] in CASES:
          r = Deck(**args)
          assert r.layers == expected_output
  
file_path: deck.gl/bindings/pydeck/tests/bindings/test_deck.py
imports: import pytest
  import json
  import pydeck
  from pydeck import Deck
  from IPython.display import HTML
  from .None import pydeck_examples
  from ..fixtures import fixtures
label_desc: Use image node_id 1 for calling a global function with example usage: test_deck_layer_args() without return types