Keep Negative (mask)
    xlabel = "Max fraction of features kept"
    ylabel = "Negative mean model output"
    transform = "negate"
    sort_order = 5

def keep_negative_mask(X, y, model_generator, method_name, num_fcounts=11):
    """ Keep Negative (mask)
    xlabel = "Max fraction of features kept"
    ylabel = "Negative mean model output"
    transform = "negate"
    sort_order = 5
    """
    return __run_measure(measures.keep_mask, X, y, model_generator, method_name, -1, num_fcounts, __mean_pred)