@Test
public void testCreateGroup() {

    Group result = engineManager.createGroup(ERROR, groupConfig);
    verify(engine, times(0)).createGroup(groupConfig);
    assertNull(result);
    result = engineManager.createGroup(engine.getEngineName(), groupConfig);
    verify(engine).createGroup(groupConfig);
    assertNotNull(result);
    assertEquals(group, result);
}