Testing localized strings in Flutter

When I try to test Widget that contains

 hintText: LocalizationResources.of(context).writecomment

I get an Exception saying:

The following NoSuchMethodError was thrown building CommentInput(dirty, state: _CommentInputState#32224): The getter 'writecomment' was called on null.

So, is there something that I'm missing? Widget builds nicely on a device and a simulator.

This is how my test looks like:

....
 final Widget widget =
        MaterialApp(home: CommentWallWidget(channelUid: '123456'), title: 'jelena',);

    await tester.pumpWidget(widget);

And the LocalizationResources is just simple l10n:

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

import 'l10n/messages_all.dart';

///class containing localization logic and string getters
class LocalizationResources {
  static Future<LocalizationResources> load(Locale locale) {
    final String name =
        locale.countryCode.isEmpty ? locale.languageCode : locale.toString();
    final String localeName = Intl.canonicalizedLocale(name);

    return initializeMessages(localeName).then((_) {
      Intl.defaultLocale = localeName;
      return LocalizationResources();
    });
  }

  static LocalizationResources of(BuildContext context) {
    return Localizations.of<LocalizationResources>(
        context, LocalizationResources);
  }
....