Unhandled Exception: Binding has not yet been initialized.

FlutterアプリにFirebaseを導入した。pub get後に関数(analyticsのメソッド)を呼び出したらエラーが発生した。

E/flutter ( 6837): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: Binding has not yet been initialized.
E/flutter ( 6837): The "instance" getter on the ServicesBinding binding mixin is only available once that binding has been initialized.
E/flutter ( 6837): Typically, this is done by calling "WidgetsFlutterBinding.ensureInitialized()" or "runApp()" (the latter calls the former). Typically this call is done in the "void main()" method. The "ensureInitialized" method is idempotent; calling it multiple times is not harmful. After calling that method, the "instance" getter will return the binding.
E/flutter ( 6837): In a test, one can call "TestWidgetsFlutterBinding.ensureInitialized()" as the first line in the test's "main()" method to initialize the binding.
E/flutter ( 6837): If ServicesBinding is a custom binding mixin, there must also be a custom binding class, like WidgetsFlutterBinding, but that mixes in the selected binding, and that is the class that must be constructed before using the "instance" getter.

メッセージの通り、runApp の前に WidgetsFlutterBinding.ensureInitialized()を呼び出したところ、エラーが解消した。

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  runApp(const MyApp());
}