public String getSnapshotString() {
        if (this.rawString == null) {
            // It's essential that we use the same locale
            Calendar current = Calendar.getInstance(Locale.US);
            current.setTime(this.snapshotDate);
            this.rawString = String.format("%02dw%02d%s",
                    current.get(Calendar.YEAR) % 100,
                    current.get(Calendar.WEEK_OF_YEAR),
                    (char) ('a' + this.snapshotWeekVersion));
        }
        return this.rawString;
    }
Retrieve the raw snapshot string (yy'w'ww[a-z]).

@return The snapshot string.
helper/src/main/java/me/lucko/helper/reflect/SnapshotVersion.java