code: def test_layer_facet(basic_chart):
      chart = (basic_chart + basic_chart).facet(row="row:Q")
      assert chart.data is not alt.Undefined
      assert chart.spec.data is alt.Undefined
      for layer in chart.spec.layer:
          assert layer.data is alt.Undefined
  
      dct = chart.to_dict()
      assert "data" in dct
  
imports: import io
  import json
  import operator
  import os
  import pathlib
  import tempfile
  import jsonschema
  import pytest
  import pandas
  import altair.vegalite.v5
label_desc: Use image node_id 36 for calling a global function with example usage: test_layer_facet(basic_chart) without return types