first method

DateTime? first(Iterable<DateTime?>? dates)

Returns the earliest (oldest) DateTime from an iterable.

Ignores any null values within the list. Returns null if the iterable is null or contains no valid dates after filtering.

Implementation

DateTime? first(Iterable<DateTime?>? dates) {
  if (dates == null) return null;
  final filteredDates = dates.whereType<DateTime>();
  if (filteredDates.isEmpty) return null;
  return filteredDates.reduce((a, b) => a.isBefore(b) ? a : b);
}