public int findIfKeyExist(Key key) {
        int index = hash(key, ht);
        int index0 = index;
        int i = 0;
        for (int j = 0; j < table.length; j++) {

            try {
                if (table[index].key.equals(key)) {
                    return index;
                }
            } catch (NullPointerException e) {
                return -1;
            }
            i++;
            index = (index0 + i * hash2(key)) % table.length;
        }
        return -1;
    }