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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, u=0):
 """ Predict next position using the Kalman filter state propagation equations for each filter in the bank. Parameters u : np.array Optional control vector. If non-zero, it is multiplied by B to create the control input into the system. """


        for f in self.filters:
            f.predict(u)

        # save prior
        self.x_prior = self.x.copy()
        self.P_prior = self.P.copy()