code: def test_arma_acf_compare_R_ARMAacf():
      # Test specific cases against output from R's ARMAacf
      bd_example_3_3_2 = arma_acf([1, -1, 0.25], [1, 1])
      assert_allclose(
          bd_example_3_3_2, results_arma_acf.bd_example_3_3_2
      )
      example_1 = arma_acf([1, -1, 0.25], [1, 1, 0.2])
      assert_allclose(example_1, results_arma_acf.custom_example_1)
      example_2 = arma_acf([1, -1, 0.25], [1, 1, 0.2, 0.3])
      assert_allclose(example_2, results_arma_acf.custom_example_2)
      example_3 = arma_acf([1, -1, 0.25], [1, 1, 0.2, 0.3, -0.35])
      assert_allclose(example_3, results_arma_acf.custom_example_3)
      example_4 = arma_acf([1, -1, 0.25], [1, 1, 0.2, 0.3, -0.35, -0.1])
      assert_allclose(example_4, results_arma_acf.custom_example_4)
      example_5 = arma_acf([1, -1, 0.25, -0.1], [1, 1, 0.2])
      assert_allclose(example_5, results_arma_acf.custom_example_5)
      example_6 = arma_acf([1, -1, 0.25, -0.1, 0.05], [1, 1, 0.2])
      assert_allclose(example_6, results_arma_acf.custom_example_6)
      example_7 = arma_acf(
          [1, -1, 0.25, -0.1, 0.05, -0.02], [1, 1, 0.2]
      )
      assert_allclose(example_7, results_arma_acf.custom_example_7)
  
imports: from statsmodels.compat.pandas import QUARTER_END
  import datetime
  import numpy
  from numpy.testing import assert_, assert_allclose, assert_almost_equal, assert_array_almost_equal, assert_equal, assert_raises
  import pandas
  import pytest
  from statsmodels.sandbox.tsa.fftarma import ArmaFft
  from statsmodels.tsa.arima.model import ARIMA
  from statsmodels.tsa.arima_process import ArmaProcess, arma_acf, arma_acovf, arma_generate_sample, arma_impulse_response, index2lpol, lpol2index, lpol_fiar, lpol_fima
  from statsmodels.tsa.tests.results import results_arma_acf
  from statsmodels.tsa.tests.results.results_process import armarep
label_desc: Use image node_id 4 for calling a global function with example usage: test_arma_acf_compare_R_ARMAacf() without return types