code: def test_spaces(unittest):
      df = replacements_data()
      data_id, replacement_type = "1", "spaces"
      build_data_inst({data_id: df})
  
      builder = ColumnReplacement(data_id, "b", replacement_type, {})
      verify_builder(
          builder,
          lambda col: unittest.assertEqual(
              list(col.values), ["", np.nan, " - "]
          ),
      )
  
      builder = ColumnReplacement(
          data_id, "b", replacement_type, {"value": "blah"}
      )
      verify_builder(
          builder,
          lambda col: unittest.assertEqual(
              list(col.values), ["", "blah", " - "]
          ),
      )
  
file_path: dtale/tests/dtale/test_replacements.py
imports: import json
  import numpy
  import pandas
  import pytest
  import sklearn
  from pkg_resources import parse_version
  from six import PY3
  from dtale.column_replacements import ColumnReplacement
  from tests.dtale.test_views import app
  from tests.dtale import build_data_inst, build_dtypes
label_desc: Use image node_id 3 for calling a global function with example usage: test_spaces(unittest) without return types