copyWith method Null safety

Implementation

SpeechPackage copyWith(
    {String? id,
    String? name,
    String? lang,
    String? url,
    String? version,
    List<SpeechCondition>? conditions}) {
  return SpeechPackage(
    id: id ?? this.id,
    name: name ?? this.name,
    lang: lang ?? this.lang,
    url: url ?? this.url,
    version: version ?? this.version,
    conditions: conditions ?? this.conditions,
  );
}