code: def test_valid_chart_w_invalid_candlestick_chart():
      assert not chart_utils.valid_chart("candlestick", cs_x=None)
      assert chart_utils.valid_chart(
          "candlestick",
          cs_x="x",
          cs_open="open",
          cs_close="close",
          cs_high="high",
          cs_low="low",
      )
  
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 3 for calling a global function with example usage: test_valid_chart_w_invalid_candlestick_chart() without return types