public static Map<String, Long> getExtensionTableKeyCounts() {
        final Map<String, Long> result = new TreeMap<>();
        try {
            return withAccessLock(() -> {
                try (Cursor cursor = database.rawQuery("SELECT _type, COUNT(*) FROM " + dbTableExtension + " GROUP BY _type", null)) {
                    while (cursor.moveToNext()) {
                        result.put(DBExtensionType.getNameFor(cursor.getInt(0)), cursor.getLong(1));
                    }
                    return result;
                }
            });
        } catch (RuntimeException re) {
            Log.w("Exception retrieving extensionTableInfo", re);
            return result;
        }
    }
migrate most recent history waypoints (up to 5)
(temporary workaround for on demand migration of the old "go to" history,
should be removed after some grace period, probably end of 2020?)
main/src/main/java/cgeo/geocaching/storage/DataStore.java