code: def test_columnar_convert_selected_columns():
      df = _EMPTY_DF.assign(before="abc", same=10)
  
      converter = ColumnarConverter(
          name="some_name",
          default_type="foo",
          type_column=None,
          column_defaults={},
          selected_columns={"before": "after", "same": "same"},
          transform_columns={},
      )
      ids, columns, type_info = converter.convert({"x": df, "y": df})
  
      np.testing.assert_array_equal(ids, [1, 2, 1, 2])
      _check_type_info(
          type_info, [("x", _empty_array(2)), ("y", _empty_array(2))]
      )
  
      assert "before" not in columns
      np.testing.assert_array_equal(columns["after"], "abc")
      np.testing.assert_array_equal(columns["same"], 10)
  
imports: import networkx
  import numpy
  import pandas
  import pytest
  from stellargraph.core.convert import ColumnarConverter, convert_nodes, convert_edges, from_networkx
  from stellargraph.core.indexed_array import IndexedArray
label_desc: Use image node_id 4 for calling a global function with example usage: test_columnar_convert_selected_columns() without return types