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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 predict(self,Xstar):
 """ predict on Xstar """

        KV = self._update_cache()
        self.covar.setXstar(Xstar)
        Kstar = self.covar.Kcross()
        Ystar = SP.dot(Kstar,KV['alpha'])
        return Ystar