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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 save(self, X=None, w=None, A=None):
 """Save one "page" of history at a given time. .. note:: This method is used internally by `SMC` to store the state of the particle system at each time t. In most cases, users should not have to call this method directly. """

        self.X.append(X)
        self.wgt.append(w)
        self.A.append(A)