presto-main/src/main/java/io/prestosql/type/setdigest/SetDigest.java/SetDigest/estimatedInMemorySize
class SetDigest:    public int estimatedInMemorySize()
    {
        return hll.estimatedInMemorySize() + minhash.size() * SIZE_OF_ENTRY + SIZE_OF_SETDIGEST + SIZE_OF_RBTREEMAP;
    }