code: def test_cmf(self):
      result = pandas_ta.cmf(
          self.high, self.low, self.close, self.volume_
      )
      self.assertIsInstance(result, Series)
      self.assertEqual(result.name, "CMF_20")
  
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 TestVolume obj's underlying member method code with example usage: obj.test_cmf() without return types