Added missing import in ref/models/database-functions.txt.
@@ -357,7 +357,7 @@ Each class is also a ``Transform`` registered on ``DateTimeField`` as
>>> from django.db.models.functions import (
... ExtractDay, ExtractHour, ExtractMinute, ExtractMonth,
... ExtractQuarter, ExtractSecond, ExtractWeek, ExtractWeekDay,
- ... ExtractYear,
+ ... ExtractIsoYear, ExtractYear,
... )
>>> start_2015 = datetime(2015, 6, 15, 23, 30, 1, tzinfo=timezone.utc)
>>> end_2015 = datetime(2015, 6, 16, 13, 11, 27, tzinfo=timezone.utc)
