@Test
public void testGetInstanceGroupConfigsWhenInstanceDefinitionsObjectIsEmpty()
{

    // Create objects required for testing.
    final InstanceDefinitions instanceDefinitions = new InstanceDefinitions();
    // Mock the external calls.
    when(emrHelper.isInstanceDefinitionsEmpty(instanceDefinitions)).thenReturn(true);
    // Call the method under test.
    List<InstanceGroupConfig> result = emrDaoImpl.getInstanceGroupConfigs(instanceDefinitions);
    // Verify the external calls.
    verify(emrHelper).isInstanceDefinitionsEmpty(instanceDefinitions);
    verifyNoMoreInteractionsHelper();
    // Validate the results.
    assertNull(result);
}