class IntrospectorImpl(model: ModuleImpl) : Introspector<ModuleImpl>(model) {
    private inner class SchemaRetriever(transaction: Any) : Introspector<ModuleImpl>.SchemaRetriever(transaction) {
        internal fun retrieve() {
            inSchema { schema -> println(schema) }
        }
    }
}

class ModuleImpl : Model {
    override fun modify(modifier: ModelModifier) {}
}