```dart title="Dart" import 'package:kreuzberg/kreuzberg.dart'; Future main() async { // Custom document extractors cannot be registered from Dart. While // registerDocumentExtractor exists in the KreuzbergBridge API, there is // no createDocumentExtractorDartImpl factory to construct a Dart-based // extractor implementation. // // Built-in extractors are registered automatically when the library // initializes. Custom extractors must be written in Rust and linked into // a Rust shim crate before the Dart host process loads the dynamic library. } ```