code: def test_supertrend_ext(self):
      self.data.ta.supertrend(append=True)
      self.assertIsInstance(self.data, DataFrame)
      self.assertEqual(
          list(self.data.columns[-4:]),
          [
              "SUPERT_7_3.0",
              "SUPERTd_7_3.0",
              "SUPERTl_7_3.0",
              "SUPERTs_7_3.0",
          ],
      )
  
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 28 for calling the TestOverlapExtension obj's underlying member method code with example usage: obj.test_supertrend_ext() without return types