code: def test_valid_chart():
      assert not chart_utils.valid_chart(
          chart_type="line", x="a", y="b", agg="rolling"
      )
      assert not chart_utils.valid_chart(
          chart_type="line", x="a", y="b", agg="rolling", window=10
      )
      assert not chart_utils.valid_chart(
          chart_type="line",
          x="a",
          y="b",
          agg="rolling",
          rolling_comp="sum",
      )
      assert chart_utils.valid_chart(
          chart_type="line",
          x="a",
          y="b",
          agg="rolling",
          window=10,
          rolling_comp="sum",
      )
  
file_path: dtale/tests/dtale/test_charts.py
imports: import pandas
  import pytest
  import dtale.charts.utils
  from dtale.constants import CHART_JOINER_CHAR
label_desc: Use image node_id 6 for calling a global function with example usage: test_valid_chart() without return types