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void main() {
  const invalidRating = -0.2; // Valid number, but not valid rating :(.
  const rating = Rating.valid(0.2); // Error on `Rating.valid(-1)`, it's negative.
  final validRating = Rating(invalidRating); // Will be clamped to 0.

  final list = [rating, validRating];
  print('Runtime type of list: ${list.runtimeType}'); // Prints "List<num>".
  final readOnlyList = ReadOnlyList(list);
  final unmodifiableList = List<num>.unmodifiable(list);
  print('UnmodifiableList length: ${unmodifiableList.length}'); // Prints "2".

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void main() {
  // Positive numbers
  print(3.2.toInt());   // 3 (truncates decimal)
  print(3.2.round());   // 3 (rounds to nearest)
  
  print(3.7.toInt());   // 3 (truncates decimal)
  print(3.7.round());   // 4 (rounds to nearest)
  
  print(3.5.toInt());   // 3 (truncates decimal)
  print(3.5.round());   // 4 (rounds away from zero)

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import "package:flutter/material.dart";

class WidgetOrElse<T extends Object> extends StatelessWidget {
  const WidgetOrElse(
    this.value,
    this._builder, {
    this.orElse = const Offstage(),
    super.key,
  });

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import "dart:math";

import "package:flutter/material.dart";

void main() => runApp(const Main());

class Main extends StatefulWidget {
  const Main({super.key});

  @override

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class BadPerson {
  const BadPerson(
    this.id, {
    required this.firstName,
    required this.lastName,
    this.email,
    this.age,
  });

  final int id;

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import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';

mixin StateNotifierMixin<State extends Object> on BlocBase<State> {
  /// Emits short, notification-like state.
  ///
  /// - `notifyDelay`: By default, one event-loop tick `Duration.zero` is used.

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import 'package:flutter/widgets.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) => WidgetsApp(
        builder: (_, __) => const MyWidget(),

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// --- Regular Way ---

const constantValue = 100; // Have to remember exact name (no IDE help) :(

class _Constant {
  // A little bit better...
  static const value = 100; // But what about final instance = _Constant();?
}

// --- Smarter Way ---

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Sharing Dart (Workshop) instructions with Github Gist

To share Dartpad links for instructions you can use Github Gist with rich markdown support (basically Dartpad Workshop directly from the Gist). This trick eliminates the need for a server, deploys, or repositories, and it also works with "secret gists". Here are the steps to follow:

1. Go to Github Gist.
2. Create a new Gist and provide a description.
3. Add your markdown instructions as an instructions.md file, for example:

## Instructions

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import 'package:meta/meta.dart';

@immutable
class Currency {
  const Currency({
    required this.iso4217code,
    required this.name,
    this.disambiguateSymbol,
    this.priority = 100,
    this.smallestDenomination = 1,