code: def test_init_propertyvaluecolumndata_copy(self) -> None:
      data = dict(a=[1], b=[2])
      cd = bms.ColumnDataSource(data).data
      ds = bms.ColumnDataSource(data=cd)
      assert ds.data == cd
      assert id(ds.data) != id(cd)
      ds.data["a"][0] = 2
      assert cd["a"][0] == 2
  
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 20 for calling the TestColumnDataSource obj's underlying member method code with example usage: obj.test_init_propertyvaluecolumndata_copy() without return types