/// <summary>
/// Add asset that is not part of solution to be part of this snapshot.
///
/// TODO: currently, this asset must be something <see cref="Serializer"/> can understand
/// this should be changed so that custom serializer can be discoverable by <see cref="ChecksumObject.Kind"/>
/// </summary>
public void AddAdditionalAsset(Asset asset, CancellationToken cancellationToken)
{
_tree.AddAdditionalAsset(asset, cancellationToken);
}