Method addAt0

core/src/main/java/io/questdb/std/ObjHashSet.java:153–162

(int index, T key)

    }

    private boolean addAt0(int index, T key) {
        if (index > -1) {
            keys[index] = key;
            if (--free == 0) {
                rehash();
            }
            return true;
        }
        return false;
    }

    private void erase(int index) {
        ((Object[]) keys)[index] = noEntryKey;