'Return a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a DateField value using a year
lookup.
`value` is an int, containing the looked-up year.'

def year_lookup_bounds_for_date_field(self, value):

    first = datetime.date(value, 1, 1)
    second = datetime.date(value, 12, 31)
    first = self.adapt_datefield_value(first)
    second = self.adapt_datefield_value(second)
    return [first, second]
