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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 update(self):
 """Determine all AR coefficients. ar_coefs([[1.0, 2.0], [1.0, nan]]) Note that updating parameter `ar_coefs` sets the shape of the log sequence |LogOut| automatically. logout([[nan, nan], [nan, nan]]) """

        pars = self.subpars.pars
        coefs = pars.control.responses.ar_coefs
        self.shape = coefs.shape
        self(coefs)
        pars.model.sequences.logs.logout.shape = self.shape