changedBody: String,
        changedAssertion: (ClassFixture) -> Unit
    ): ClassChangeFixture {
        val initialClass = compileClass(className, initialBody)
        initialAssertion(initialClass)
        val changedClass = compileClass(className, changedBody)
        changedAssertion(changedClass)
        return ClassChangeFixture(initialClass, changedClass)
    }

    private
    fun givenChangingObject(