def METHOD_NAME(self, free=True):
    PI2 = np.pi * 0.5
    b1 = np.asarray([[0, PI2] for _ in range(self.dim)])
    b2 = np.asarray([[-PI2, PI2] for _ in range(self.dim)])
    if free:
        return np.concatenate((b1[self.free], b2[self.slope_free]))
    else:
        return np.concatenate((b1, b2))