@Test
public void testGetEmrClusterDefinitionKeys()
{

    // Create a namespace entity.
    NamespaceEntity namespaceEntity = new NamespaceEntity();
    // Create a list of EMR cluster definition keys.
    List<EmrClusterDefinitionKey> emrClusterDefinitionKeys = Lists.newArrayList(new EmrClusterDefinitionKey(NAMESPACE, EMR_CLUSTER_DEFINITION_NAME));
    // Mock the external calls.
    when(namespaceDao.getNamespaceByCd(NAMESPACE)).thenReturn(namespaceEntity);
    when(emrClusterDefinitionDao.getEmrClusterDefinitionKeysByNamespace(namespaceEntity)).thenReturn(emrClusterDefinitionKeys);
    // Call the method under test.
    List<EmrClusterDefinitionKey> result = emrClusterDefinitionDaoHelper.getEmrClusterDefinitionKeys(NAMESPACE);
    // Verify the external calls.
    verify(namespaceDao).getNamespaceByCd(NAMESPACE);
    verify(emrClusterDefinitionDao).getEmrClusterDefinitionKeysByNamespace(namespaceEntity);
    verifyNoMoreInteractionsHelper();
    // Validate the result.
    assertEquals(emrClusterDefinitionKeys, result);
}