public void howToSpecifyUpdateConditions() {
final String phoneNumberToAdd = "987-654-3210";
Table table = dynamo.getTable(TABLE_NAME);
System.out.println(table.getItemOutcome(HASH_KEY, FIRST_CUSTOMER_ID, RANGE_KEY, ADDRESS_TYPE_WORK));
try {
table.updateItem(HASH_KEY, FIRST_CUSTOMER_ID, RANGE_KEY, ADDRESS_TYPE_WORK,
// Specifies the criteria that the "phone" attribute must exist
// as a precondition to adding the phone number
Arrays.asList(new Expected("phone").exists()),
// Adds the phone number if the expectation is satisfied
new AttributeUpdate("phone").addElements(phoneNumberToAdd));