def METHOD_NAME(self, r, sigma0, r_core):
    """Mass enclosed in cylinder of radius r.
    :param r: radius (angular scale)
    :param sigma0: convergence in the core
    :param r_core: core radius
    :return: mass enclosed in cylinder of radius r
    """
    return self.alpha_r(r, sigma0, r_core) * np.pi * r