code: def test_chart_operations():
      data = pd.DataFrame(
          {
              "x": pd.date_range("2012", periods=10, freq="Y"),
              "y": range(10),
              "c": list("abcabcabca"),
          }
      )
      chart1 = (
          alt.Chart(data).mark_line().encode(x="x", y="y", color="c")
      )
      chart2 = chart1.mark_point()
      chart3 = chart1.mark_circle()
      chart4 = chart1.mark_square()
  
      chart = chart1 + chart2 + chart3
      assert isinstance(chart, alt.LayerChart)
      assert len(chart.layer) == 3
      chart += chart4
      assert len(chart.layer) == 4
  
      chart = chart1 | chart2 | chart3
      assert isinstance(chart, alt.HConcatChart)
      assert len(chart.hconcat) == 3
      chart |= chart4
      assert len(chart.hconcat) == 4
  
      chart = chart1 & chart2 & chart3
      assert isinstance(chart, alt.VConcatChart)
      assert len(chart.vconcat) == 3
      chart &= chart4
      assert len(chart.vconcat) == 4
  
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 7 for calling a global function with example usage: test_chart_operations() without return types