Users want to get rounding mode in `quantileExact` equivalent to "median_low" from Python:
https://docs.python.org/3/library/statistics.html#statistics.median_low
while current implementation works equivalent to "median_high" (?)
if (!array.empty())
        {
            size_t prev_n = 0;
            for (size_t i = 0; i < size; ++i)
            {
                auto level = levels[indices[i]];
                Float64 h = level * (array.size() - 1) + 1;
                auto n = static_cast<size_t>(h);
                if (n >= array.size())
                    result[indices[i]] = static_cast<Float64>(array[array.size() - 1]);
                else if (n < 1)
                    result[indices[i]] = static_cast<Float64>(array[0]);
                else
                {
                    std::nth_element(array.begin() + prev_n, array.begin() + n - 1, array.end());
                    auto nth_element = std::min_element(array.begin() + n, array.end());
                    result[indices[i]] = static_cast<Float64>(array[n - 1]) + (h - n) * static_cast<Float64>(*nth_element - array[n - 1]);
                    prev_n = n - 1;
                }
            }
        }
        else
        {
            for (size_t i = 0; i < size; ++i)
                result[i] = std::numeric_limits<Float64>::quiet_NaN();
        }
    }
};
}