anchor.diff:  
   /// Class for information provided to [FlutterExceptionHandler] callbacks.
   ///
  -/// See [FlutterError.onError].
  +///  {@tool snippet}
  +/// This is an example of using [FlutterErrorDetails] when calling
  +/// [FlutterError.reportError].
  +///
  +/// ```dart
  +/// void main() {
  +///   try {
  +///     // Try to do something!
  +///   } catch (error) {
  +///     // Catch & report error.
  +///     FlutterError.reportError(FlutterErrorDetails(
  +///       exception: error,
  +///       library: 'Flutter test framework',
  +///       context: ErrorSummary('while running async test code'),
  +///     ));
  +///   }
  +/// }
  +/// ```
  +/// {@end-tool}
  +///
  +/// See also:
  +///
  +///   * [FlutterError.onError], which is called whenever the Flutter framework
  +///     catches an error
   class FlutterErrorDetails with Diagnosticable {
     /// Creates a [FlutterErrorDetails] object with the given arguments setting
     /// the object's properties.
  
positive.code: import 'diagnostics.dart';
  import 'print.dart';
  import 'stack_frame.dart';
  
  /// Signature for [FlutterError.onError] handler.
  typedef FlutterExceptionHandler = void Function(FlutterErrorDetails details);
  
negative.code: 
  /// An [ErrorHint] provides specific, non-obvious advice that may be applicable.
  ///
  /// If your message provides obvious advice that is always applicable, it is an
  /// [ErrorDescription] not a hint.
  ///
  /// See also:
  