copyWith method
Implementation
Nip01Event copyWith({
  String? pubKey,
  int? createdAt,
  int? kind,
  List<List<String>>? tags,
  String? content,
  String? sig,
  List<String>? sources,
}) {
  return Nip01Event._(
    id,
    pubKey ?? this.pubKey,
    createdAt ?? this.createdAt,
    kind ?? this.kind,
    tags ?? this.tags,
    content ?? this.content,
    sig ?? this.sig,
  )..sources = sources ?? this.sources;
}