code: def test_pandas_univariate_dateindex_repetitions():
      # Simulation will maintain have date index
      ix = pd.date_range(start="2000", periods=2, freq=MONTH_END)
      endog = pd.Series(np.zeros(2), index=ix)
      mod = sarimax.SARIMAX(endog)
      res = mod.filter([0.5, 1.0])
  
      # Default simulate anchors to the start of the sample
      actual = res.simulate(
          2,
          state_shocks=np.zeros(2),
          initial_state=np.zeros(1),
          repetitions=2,
      )
      ix = pd.date_range(start="2000-01", periods=2, freq=MONTH_END)
      columns = pd.MultiIndex.from_product([["y"], [0, 1]])
      desired = pd.DataFrame(
          np.zeros((2, 2)), index=ix, columns=columns
      )
      assert_allclose(actual, desired)
      assert_(actual.columns.equals(desired.columns))
  
      # Alternative anchor changes the index
      actual = res.simulate(
          2,
          anchor=2,
          state_shocks=np.zeros(2),
          initial_state=np.zeros(1),
          repetitions=2,
      )
      ix = pd.date_range(start="2000-03", periods=2, freq=MONTH_END)
      columns = pd.MultiIndex.from_product([["y"], [0, 1]])
      desired = pd.DataFrame(
          np.zeros((2, 2)), index=ix, columns=columns
      )
      assert_allclose(actual, desired)
      assert_(actual.index.equals(desired.index))
      assert_(actual.columns.equals(desired.columns))
  
imports: from statsmodels.compat.pandas import MONTH_END
  import numpy
  from numpy.testing import assert_, assert_allclose, assert_equal
  import pandas
  import pytest
  from scipy.signal import lfilter
  from statsmodels.tools.sm_exceptions import EstimationWarning, SpecificationWarning
  from statsmodels.tsa.statespace import dynamic_factor, sarimax, structural, varmax
  from .test_impulse_responses import TVSS
label_desc: Use image node_id 37 for calling a global function with example usage: test_pandas_univariate_dateindex_repetitions() without return types