code: def test_valid_chart_w_invalid_treemap_chart():
      assert not chart_utils.valid_chart("treemap", treemap_value=None)
      assert not chart_utils.valid_chart(
          "treemap", treemap_value="a", treemap_label=None
      )
      assert chart_utils.valid_chart(
          "treemap", treemap_value="x", treemap_label="open"
      )
  
file_path: dtale/tests/dtale/charts/test_utils.py
imports: import mock
  import pytest
  import dtale.charts.utils
  from tests import ExitStack
  from tests.dtale.test_charts import build_col_def
label_desc: Use image node_id 4 for calling a global function with example usage: test_valid_chart_w_invalid_treemap_chart() without return types