code: def test_cdl_z(self):
      result = pandas_ta.cdl_z(
          self.open, self.high, self.low, self.close
      )
      self.assertIsInstance(result, DataFrame)
      self.assertEqual(result.name, "CDL_Z_30_1")
  
file_path: pandas-ta/tests/test_indicator_candle.py
imports: from .config import error_analysis, sample_data, CORRELATION, CORRELATION_THRESHOLD, VERBOSE
  from .context import pandas_ta
  from unittest import TestCase, skip
  import pandas.testing
  from pandas import DataFrame, Series
  import talib
label_desc: Use image node_id 9 for calling the TestCandle obj's underlying member method code with example usage: obj.test_cdl_z() without return types