asset method

Implementation

MultiAssetBuilder asset(CurrencyAsset asset) {
  final nativeAsset = ShelleyMultiAsset(policyId: asset.policyId, assets: [
    ShelleyAsset(name: asset.assetName, value: int.parse(asset.quantity)),
  ]);
  _multiAssets.add(nativeAsset);
  return this;
}