Method from

base/src/main/java/net/time4j/DayPeriod.java:743–752

(
            Locale locale,
            AttributeQuery attributes
        )

        }

        private static DayPeriod from(
            Locale locale,
            AttributeQuery attributes
        ) {
            if (attributes.contains(CUSTOM)) {
                return attributes.get(CUSTOM);
            }

            return DayPeriod.of(locale, attributes.get(Attributes.CALENDAR_TYPE, CalendarText.ISO_CALENDAR_TYPE));
        }
    }

    static class Element