@Test
public void testCreateUser() {

    User result = engineManager.createUser(ERROR, userConfig);
    verify(engine, times(0)).createUser(userConfig);
    assertNull(result);
    result = engineManager.createUser(engine.getEngineName(), userConfig);
    verify(engine).createUser(userConfig);
    assertNotNull(result);
    assertEquals(user, result);
}