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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def calc_next_ma_coef(self, ma_order, ma_model):
 """Determine the MA coefficients of the ARMA model based on its predetermined AR coefficients and the MA ordinates of the given |MA| model. The MA coefficients are determined one at a time, beginning with the first one. Each ARMA MA coefficient in set in a manner that allows for the exact reproduction of the equivalent pure MA coefficient with all relevant ARMA coefficients. """

        idx = ma_order-1
        coef = ma_model.coefs[idx]
        for jdx, ar_coef in enumerate(self.ar_coefs):
            zdx = idx-jdx-1
            if zdx >= 0:
                coef -= ar_coef*ma_model.coefs[zdx]
        self.ma_coefs = numpy.concatenate((self.ma_coefs, [coef]))