How to Test Builder - 4

AnswerWithPairList.kt

class AnswerWithPairList(private val clazz: Class<*>, private val pairs: List<Pair<Class<*>, *>>) : Answer<Any> {
    private val delegate = ReturnsEmptyValues()

    @Throws(Throwable::class)
    override fun answer(invocation: InvocationOnMock): Any = invocation.apply {
        val returnType = method.returnType
        return if (returnType == clazz) mock
        else pairs.find { returnType == it.first }?.second ?: delegate.answer(this)
    }
}