Imperative Java Shit

gistfile1.java

private String getCustomerKeys(List<Customer> customers) {
	StringBuilder keys = new StringBuilder();
	if (customers != null) {
		for (Customer customer: customers) {
			if (keys.length() > 0) {
				keys.append(", ");
			}
			keys.append(customer.customerKey.toString());
		}
		return keys.toString();
	}
	return null;
}