presto-main/src/main/java/io/prestosql/operator/aggregation/TypedSet.java/TypedSet/getHashPositionOfElement
class TypedSet:    private int getHashPositionOfElement(Block block, int position)
    {
        int hashPosition = getMaskedHash(hashPosition(elementType, block, position));
        while (true) {
            int blockPosition = blockPositionByHash.get(hashPosition);
            if (blockPosition == EMPTY_SLOT) {
                // Doesn't have this element
                return hashPosition;
            }
            if (isContainedAt(block, position, blockPosition)) {
                // Already has this element
                return hashPosition;
            }

            hashPosition = getMaskedHash(hashPosition + 1);
        }
    }