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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 _det_inference(self):
 """ Internal method for determining the inference method """

        # 2 random effects with complete design -> gp2KronSum
        # TODO: add check for low-rankness, use GP3KronSumLR and GP2KronSumLR when possible
        if (self.n_randEffs==2) and (~sp.isnan(self.Y).any()):
            rv = 'GP2KronSum'
        else:
            rv = 'GP'
        return rv