sneaky-part1-8.java

private void handleAllOrdersOf(List<Customer> customers) {
    Optional.ofNullable(customers)
        .map(unchecked(this::queryDatabaseForAllOrders)) // Sneaky throw, SQLException
        .orElseGet(Collections::emptyList)
        .forEach(this::processOrder);
}

public List queryDatabaseForAllOrders(List<Customer> customers) throws SQLException {
    // Query database, retrieve all orders for all customers
}