How can I initialize variable before each test using kotlin-test framework

I'm trying to find a way to set up variable before each test. Just like the @Before method in Junit. Go through the doc from kotlin-test, I found that I can use interceptTestCase() interface. But unfortunately, the code below will trigger exception:

kotlin.UninitializedPropertyAccessException: lateinit property text has not been initialized

class KotlinTest: StringSpec() {
lateinit var text:String
init {
    "I hope variable is be initialized before each test" {
        text shouldEqual "ABC"
    }

    "I hope variable is be initialized before each test 2" {
        text shouldEqual "ABC"
    }
}

override fun interceptTestCase(context: TestCaseContext, test: () -> Unit) {
    println("interceptTestCase()")
    this.text = "ABC"
    test()
}
}

Am I in the wrong way to use interceptTestCase()? Thank you very much~