Method from

base/src/main/java/net/time4j/PlainDate.java:924–932

(GregorianDate date)

     * @return  PlainDate
     */
    public static PlainDate from(GregorianDate date) {

        if (date instanceof PlainDate) {
            return (PlainDate) date;
        } else {
            return PlainDate.of(date.getYear(), date.getMonth(), date.getDayOfMonth());
        }

    }

    /**
     * <p>Short cut for {@code TemporalType.LOCAL_DATE.translate(date)}. </p>