code: def tearDown(self):
      if timed:
          self.time_diff = perf_counter() - self.stime
      self.added_cols = len(self.data.columns) - self.init_cols
      self.assertGreaterEqual(self.added_cols, 1)
  
      self.result = self.data[self.data.columns[-self.added_cols :]]
      self.assertIsInstance(self.result, DataFrame)
      self.data.drop(columns=self.result.columns, axis=1, inplace=True)
  
      self.speed_test[self.category] = [self.added_cols, self.time_diff]
  
imports: from multiprocessing import cpu_count
  from time import perf_counter
  from .config import sample_data
  from .context import pandas_ta
  from unittest import skip, skipUnless, TestCase
  from pandas import DataFrame
label_desc: Use image node_id 4 for calling the TestStrategyMethods obj's underlying member method code with example usage: obj.tearDown() without return types