Initialize object lateinit property for test

Question

I am using kotlin multiplatform for my project. SQLDelight is used to build the database. While writing a test for one of the classes using DataBaseCache I encountered the error lateinit property appContext has not been initialized. How can I initialize appContext (perhaps with mockk?) to a DataBaseCache object?

actual object DataBaseCache {
    lateinit var appContext: Context

    actual fun cache(): MedtorDatabase {
        val driver = AndroidSqliteDriver(MedtorDatabase.Schema, appContext, "medtor.db")
        return MedtorDatabase(driver)
    }
}