public static void removeAll(final SQLiteDatabase db, final DBExtensionType type, final String key) {
            withAccessLock(() -> {
                checkState(type, key, false);
                db.delete(dbTableExtension, "_type = ? AND _key LIKE ?", new String[]{String.valueOf(type.id), key});
            });
        }
removes all elements with this key from database
main/src/main/java/cgeo/geocaching/storage/DataStore.java