public IEnumerable <TPeriod> Pick(IEnumerable <TPeriod> periods)
{
if (_periodSelector.Pick(periods).TryGet(out var item))
{
yield return(item);
}
}
public Option <Date> Pick(IEnumerable <MonthPeriod> months)
{
var monthOption = _monthSelector.Pick(months);
return(monthOption.Select(month =>
{
var selectedDays = _daySelector.PickDays(month.Days());
return _ordinal.Pick(selectedDays);
}));
}