public override IDriverNode CreateDriverNode(IDriverContext ctx)
        {
            BitcoinValueNode node = null;

            switch (ctx.NodeInstance.This2NodeTemplateNavigation.Key)
            {
            case "blockchain-btc-usd":
                node = new BitcoinValueNode(ctx, "USD", false, this);
                break;

            case "blockchain-btc-eur":
                node = new BitcoinValueNode(ctx, "EUR", false, this);
                break;

            case "blockchain-btc-usd-with-symbol":
                node = new BitcoinValueNode(ctx, "USD", true, this);
                break;

            case "blockchain-btc-eur-with-symbol":
                node = new BitcoinValueNode(ctx, "EUR", true, this);
                break;
            }

            AddNode(node);

            return(node);
        }
 internal void AddNode(BitcoinValueNode node)
 {
     if (node != null)
     {
         _nodes.Add(node);
     }
 }