code: def test_trend_change(self):
      print("-" * 80)
      logger.info("test_trend_change\n" + "-" * 80 + "\n")
  
      # test strictly positive trend changes
      trend = TrendChange(
          anom_prob=0.2, pos_prob=1.0, scale_range=(2, 3)
      )
      anom_ts = trend(self.ts)
      self.assertTrue(
          all(
              self.ts.univariates["metric"].np_values
              <= anom_ts.univariates["metric"].np_values
          )
      )
  
      # test strictly negative trend changes
      trend = TrendChange(
          anom_prob=0.2, pos_prob=0.0, scale_range=(2, 3)
      )
      anom_ts = trend(self.ts)
      self.assertTrue(
          all(
              self.ts.univariates["metric"].np_values
              >= anom_ts.univariates["metric"].np_values
          )
      )
  
file_path: merlion/tests/transform/test_anomalize.py
imports: import logging
  from os.path import abspath, dirname
  import sys
  import unittest
  import numpy
  from merlion.utils.ts_generator import TimeSeriesGenerator
  from merlion.transform.anomalize import Shock, TrendChange
label_desc: Use image node_id 3 for calling the TestAnomalize obj's underlying member method code with example usage: obj.test_trend_change() without return types