code: def test_spec_to_json_mimebundle():
      bundle = spec_to_mimebundle(
          spec=vegalite_spec,
          mode="vega-lite",
          format="json",
      )
      assert bundle == {"application/json": vegalite_spec}
  
file_path: altair/tests/utils/test_mimebundle.py
imports: import pytest
  import altair
  from altair import VEGA_VERSION
  from altair.utils.mimebundle import spec_to_mimebundle
label_desc: Use image node_id 6 for calling a global function with example usage: test_spec_to_json_mimebundle() without return types