code: def test_init_dataframe_nonstring_named_multicolumn(self) -> None:
      data = {(1, 2): [1, 2], (2, 3): [2, 3]}
      df = pd.DataFrame(data)
      with pytest.raises(TypeError, match=r"Could not flatten.*"):
          bms.ColumnDataSource(data=df)
  
imports: from __future__ import annotations
  import pytest
  import datetime
  import io
  import numpy
  import pandas
  from bokeh.models import Selection
  from bokeh.util.serialization import convert_datetime_array
  from bokeh.util.warnings import BokehDeprecationWarning
  import bokeh.models.sources
label_desc: Use image node_id 14 for calling the TestColumnDataSource obj's underlying member method code with example usage: obj.test_init_dataframe_nonstring_named_multicolumn() without return types