presto-base-jdbc/src/main/java/io/prestosql/plugin/jdbc/TransactionScopeCachingJdbcClient.java/TransactionScopeCachingJdbcClient/TransactionScopeCachingJdbcClient
class TransactionScopeCachingJdbcClient:    public TransactionScopeCachingJdbcClient(JdbcClient delegate)
    {
        this.delegate = requireNonNull(delegate, "delegate is null");
    }