code: def assert_is_vega_spec(vega_spec):
      assert (
          vega_spec["$schema"]
          == "https://vega.github.io/schema/vega/v5.json"
      )
      assert "data" in vega_spec
      assert "marks" in vega_spec
      assert "scales" in vega_spec
      assert "axes" in vega_spec
  
file_path: altair/tests/utils/test_compiler.py
imports: import json
  import pytest
  from altair import vegalite_compilers, Chart
label_desc: Use image node_id 2 for calling a global function with example usage: assert_is_vega_spec(vega_spec) without return types