Creating Custom Widget in Flutter

NotificationManager.dart

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

//
// Class to generate SnackBar notifications everywhere in the app's codebase
// without being limited to Scafold inherited widgets
//
class NotificationManager {
  static BuildContext context;
  static Color successBackgroundColor = Colors.black;
  static Color errorBackgroundColor = Colors.red;

  static generateNewSuccessNotification(String message, {fast: false}) {
    SnackBar newNotification = SnackBar(
      content: Text(
        message,
        style: TextStyle(fontSize: 17),
      ),
      backgroundColor: successBackgroundColor,
      duration: Duration(milliseconds: fast ? 500 : 1000),
    );

    if (context == null) {
      return;
    }

    Scaffold.of(context).showSnackBar(newNotification);
  }

  static generateNewErrorNotification(String message, {fast: false}) {
    SnackBar newNotification = SnackBar(
      content: Text(
        message,
        style: TextStyle(fontSize: 17),
      ),
      backgroundColor: errorBackgroundColor,
      duration: Duration(milliseconds: fast ? 500 : 1000),
    );

    if (context == null) {
      return;
    }

    Scaffold.of(context).showSnackBar(newNotification);
  }
}

I really do not understand what "without being limited to Scafold inherited widgets" means. It implies once you have this class, you do not need to do showSnackBar when in fact, it does. And its a static class with static methods and a static reference to a BuildContext which can get stale at any time. And yes this implementation would break if the context used cannot find a Scaffold up the tree.