TestObserver in Java

@Nested
@DisplayName("given I flag someone")
inner class FlagSomeone {
    lateinit var testObserver: TestObserver<MatchEvent>
    lateinit var targetProfile: Profile

    @BeforeEach
    fun setup() {
        testObserver = matchViewModel.events.test()

        repeat(INSTRUCTION_CARDS_NUM) { matchViewModel.swipe(MatchRating.Interested) }

        val matchState = matchViewModel.matchState.value as MatchState.Started
        val matchItem = matchState.stack.items.lastElement() as MatchItem.ProfileCard
        targetProfile = matchItem.profile

        matchViewModel.flagButtonTapped()
    }

    @Test
    fun `then sends flagged event`() {
        testObserver.values().last() shouldBeInstanceOf MatchEvent.FlagProfile::class
        (testObserver.values().last() as MatchEvent.FlagProfile).apply {
            profile.shouldBeEqualTo(targetProfile)
        }
    }
}