code: def test_chop_ext(self):
      self.data.ta.chop(append=True, ln=False)
      self.assertIsInstance(self.data, DataFrame)
      self.assertEqual(self.data.columns[-1], "CHOP_14_1_100")
  
      self.data.ta.chop(append=True, ln=True)
      self.assertIsInstance(self.data, DataFrame)
      self.assertEqual(self.data.columns[-1], "CHOPln_14_1_100")
  
imports: from .config import sample_data
  from .context import pandas_ta
  from unittest import skip, TestCase
  from pandas import DataFrame
label_desc: Use image node_id 8 for calling the TestTrendExtension obj's underlying member method code with example usage: obj.test_chop_ext() without return types