code: def test_pct_change(self):
      pser = pd.Series([90, 91, 85], index=[2, 4, 1])
      psser = ps.from_pandas(pser)
  
      self.assert_eq(
          psser.pct_change(), pser.pct_change(), check_exact=False
      )
      self.assert_eq(
          psser.pct_change().sum(), pser.pct_change().sum(), almost=True
      )
      self.assert_eq(
          psser.pct_change(periods=2),
          pser.pct_change(periods=2),
          check_exact=False,
      )
      self.assert_eq(
          psser.pct_change(periods=-1),
          pser.pct_change(periods=-1),
          check_exact=False,
      )
      self.assert_eq(
          psser.pct_change(periods=-100000000),
          pser.pct_change(periods=-100000000),
      )
      self.assert_eq(
          psser.pct_change(periods=100000000),
          pser.pct_change(periods=100000000),
      )
  
      # for MultiIndex
      midx = pd.MultiIndex(
          [["lama", "cow", "falcon"], ["speed", "weight", "length"]],
          [[0, 0, 0, 1, 1, 1, 2, 2, 2], [0, 1, 2, 0, 1, 2, 0, 1, 2]],
      )
      pser = pd.Series(
          [45, 200, 1.2, 30, 250, 1.5, 320, 1, 0.3], index=midx
      )
      psser = ps.from_pandas(pser)
  
      self.assert_eq(
          psser.pct_change(), pser.pct_change(), check_exact=False
      )
      self.assert_eq(
          psser.pct_change().sum(), pser.pct_change().sum(), almost=True
      )
      self.assert_eq(
          psser.pct_change(periods=2),
          pser.pct_change(periods=2),
          check_exact=False,
      )
      self.assert_eq(
          psser.pct_change(periods=-1),
          pser.pct_change(periods=-1),
          check_exact=False,
      )
      self.assert_eq(
          psser.pct_change(periods=-100000000),
          pser.pct_change(periods=-100000000),
      )
      self.assert_eq(
          psser.pct_change(periods=100000000),
          pser.pct_change(periods=100000000),
      )
  
imports: import unittest
  from decimal import Decimal
  import numpy
  import pandas
  from pyspark import pandas
  from pyspark.testing.pandasutils import ComparisonTestBase
  from pyspark.testing.sqlutils import SQLTestUtils
label_desc: Use image node_id 10 for calling the SeriesStatMixin obj's underlying member method code with example usage: obj.test_pct_change() without return types