@Test
public void scanHandledMessageTypes_testSagaFound_returnsEntryWithHandlers() {

    // given
    sagaTypes.add(TestSaga.class);
    // when
    Map<Class<? extends Saga>, SagaHandlersMap> scanResult = sut.scanHandledMessageTypes();
    // then
    assertThat("Expected one entry in scan result.", scanResult.size(), equalTo(1));
    assertThat("Expected entry of key TestSage.class", scanResult.containsKey(TestSaga.class), is(true));
    SagaHandlersMap handlers = scanResult.get(TestSaga.class);
    assertThat("Expected three total message handlers for saga.", handlers.messageHandlers(), hasSize(3));
}