code: def test_aobv_ext(self):
      self.data.ta.aobv(append=True)
      self.assertIsInstance(self.data, DataFrame)
      self.assertEqual(
          list(self.data.columns[-7:]),
          [
              "OBV",
              "OBV_min_2",
              "OBV_max_2",
              "OBVe_4",
              "OBVe_12",
              "AOBV_LR_2",
              "AOBV_SR_2",
          ],
      )
      # Remove "OBV" so it does not interfere with test_obv_ext()
      self.data.drop("OBV", axis=1, inplace=True)
  
imports: from .config import sample_data
  from .context import pandas_ta
  from unittest import TestCase
  from pandas import DataFrame
label_desc: Use image node_id 8 for calling the TestVolumeExtension obj's underlying member method code with example usage: obj.test_aobv_ext() without return types