code: def acovf_explicit(ar, ma, nobs):
      """add correlation of MA representation explicitely"""
      ir = arma_impulse_response(ar, ma)
      acovfexpl = [
          np.dot(ir[: nobs - t], ir[t:nobs]) for t in range(10)
      ]
      return acovfexpl
  
imports: import numpy
  from numpy.testing import assert_array_almost_equal
  import matplotlib.pyplot
  from statsmodels import regression
  from statsmodels.tsa.arima_process import arma_generate_sample, arma_impulse_response
  from statsmodels.tsa.arima_process import arma_acovf, arma_acf
  from statsmodels.tsa.arima.model import ARIMA
  from statsmodels.tsa.stattools import acf, acovf
  from statsmodels.graphics.tsaplots import plot_acf
label_desc: Use image node_id 6 for calling a global function with example usage: acovf_explicit(ar, ma, nobs) and returns: acovfexpl