code: def test_autocorr(self, datetime_series):
      # Just run the function
      corr1 = datetime_series.autocorr()
  
      # Now run it with the lag parameter
      corr2 = datetime_series.autocorr(lag=1)
  
      # corr() with lag needs Series of at least length 2
      if len(datetime_series) <= 2:
          assert np.isnan(corr1)
          assert np.isnan(corr2)
      else:
          assert corr1 == corr2
  
      # Choose a random lag between 1 and length of Series - 2
      # and compare the result with the Series corr() function
      n = 1 + np.random.default_rng(2).integers(
          max(1, len(datetime_series) - 2)
      )
      corr1 = datetime_series.corr(datetime_series.shift(n))
      corr2 = datetime_series.autocorr(lag=n)
  
      # corr() with lag needs Series of at least length 2
      if len(datetime_series) <= 2:
          assert np.isnan(corr1)
          assert np.isnan(corr2)
      else:
          assert corr1 == corr2
  
label_desc: Use image node_id 1 for calling the TestAutoCorr obj's underlying member method code with example usage: obj.test_autocorr(datetime_series) without return types