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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 predicted_state_vec(self):
        '''The predicted state vector for the next time point

        From Welch eqn 1.9
        '''
        if not self.has_cached_predicted_state_vec:
            self.p_state_vec = dot_n(
                self.translation_matrix,
                self.state_vec[:, :, np.newaxis])[:,:,0]
        return self.p_state_vec