bool IntegerArrayHash::equal(const IntegerArray& a, const IntegerArray& b)
{
    if (a.isDeletedValue() || b.isDeletedValue())
        return a.isDeletedValue() == b.isDeletedValue();
    if (a.size() != b.size())
        return false;
    for (size_t i = 0; i < a.size(); ++i) {
        if (a.integers()[i] != b.integers()[i])
            return false;
    }
    return true;
}
 static bool isDeletedValue(const IntegerArray& array) { return array.isDeletedValue(); }