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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 IBA_alpha(self, alpha):
 """ Calculate IBA_alpha score. :param alpha: alpha parameter :type alpha: float :return: IBA_alpha score for classes as dict """

        try:
            IBA_dict = {}
            for i in self.classes:
                IBA_dict[i] = IBA_calc(self.TPR[i], self.TNR[i], alpha=alpha)
            return IBA_dict
        except Exception:
            return {}