@Test
public void testFailedWhenSystemExceptionAndErrorCauseExistsShouldLogErrorAtErrorLevel() {

    //GIVEN
    State state = Mockito.mock(State.class);
    SystemException exception = new SystemException(ERR_MSG);
    Throwable cause = new Throwable();
    exception.initCause(cause);
    //WHEN
    underTest.failed(state, exception);
    //THEN
    verify(logger).error(FAILED_MESSAGE, exception);
}