code: def test_psar_ext(self):
      self.data.ta.psar(append=True)
      self.assertIsInstance(self.data, DataFrame)
      self.assertEqual(
          list(self.data.columns[-4:]),
          [
              "PSARl_0.02_0.2",
              "PSARs_0.02_0.2",
              "PSARaf_0.02_0.2",
              "PSARr_0.02_0.2",
          ],
      )
  
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 16 for calling the TestTrendExtension obj's underlying member method code with example usage: obj.test_psar_ext() without return types