code: def test_remove_exists2(self) -> None:
      with pytest.warns(
          UserWarning,
          match=r"Unable to find column 'foo' in data source",
      ) as w:
          ds = bms.ColumnDataSource()
          ds.remove("foo")
          assert ds.column_names == []
          assert len(w) == 1
          assert w[0].category == UserWarning
          assert (
              str(w[0].message)
              == "Unable to find column 'foo' in data source"
          )
  
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 25 for calling the TestColumnDataSource obj's underlying member method code with example usage: obj.test_remove_exists2() without return types