@Test
public void testPublishListOfMachines() throws Exception {
AmazonEC2 client = mock(AmazonEC2.class);
ProviderClientCache clientCache = mock(ProviderClientCache.class);
when(clientCache.get(Matchers.<Provider>any())).thenReturn(client);
DelegateExecution execution = mock(DelegateExecution.class);
List<String> instanceIds = Lists.newArrayList("i-123", "i-456");
when(execution.getVariable(ProcessVariables.INSTANCE_IDS)).thenReturn(instanceIds);