def METHOD_NAME(self, args_lens, *args, **kwargs):
    """
    :param args_lens: array of lens model parameters being optimized, computed from kwargs_lens in a specified
     param_class, see documentation in QuadOptimizer.param_manager
    :return: the log likelihood corresponding to the given chi^2
    """
    chi_square = self.chi_square(args_lens)
    return -0.5 * chi_square