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" (?)
{
    factory.registerFunction(NameQuantile::name, createAggregateFunctionQuantile<FuncQuantile>);
    factory.registerFunction(NameQuantiles::name, createAggregateFunctionQuantile<FuncQuantiles>);