Source

List<PackageCategory> get categories {
  Map<String, PackageCategory> result = {};

  for (Library library in _libraries) {
    String name = '';

    if (library.name.startsWith('dart:')) {
      name = 'Dart Core';
    } else {
      name = library.packageName;
    }

    if (!result.containsKey(name)) {
      result[name] = new PackageCategory(name, this);
    }
    result[name]._libraries.add(library);
  }
  // Help the user if they pass us a category that doesn't exist.
  for (String categoryName in config.categoryOrder) {
    if (!result.containsKey(categoryName))
      warnOnElement(null, PackageWarning.categoryOrderGivesMissingPackageName,
          message: "${categoryName}, categories: ${result.keys.join(',')}");
  }
  List<PackageCategory> packageCategories = result.values.toList()..sort();
  return packageCategories;
}