code: def test_plot_acf(close_figures):
      # Just test that it runs.
      fig = plt.figure()
      ax = fig.add_subplot(111)
  
      ar = np.r_[1.0, -0.9]
      ma = np.r_[1.0, 0.9]
      armaprocess = tsp.ArmaProcess(ar, ma)
      rs = np.random.RandomState(1234)
      acf = armaprocess.generate_sample(100, distrvs=rs.standard_normal)
      plot_acf(acf, ax=ax, lags=10)
      plot_acf(acf, ax=ax)
      plot_acf(acf, ax=ax, alpha=None)
  
imports: from statsmodels.compat.pandas import MONTH_END
  from statsmodels.compat.python import lmap
  import calendar
  from io import BytesIO
  import locale
  import numpy
  from numpy.testing import assert_, assert_equal
  import pandas
  import pytest
  from statsmodels.datasets import elnino, macrodata
  from statsmodels.graphics.tsaplots import month_plot, plot_accf_grid, plot_acf, plot_ccf, plot_pacf, plot_predict, quarter_plot, seasonal_plot
  from statsmodels.tsa import arima_process
  from statsmodels.tsa.ar_model import AutoReg
  from statsmodels.tsa.arima.model import ARIMA
label_desc: Use image node_id 1 for calling a global function with example usage: test_plot_acf(close_figures) without return types