anchor.diff:                readNavigationLabel(navigationListChildNode);
             result.NavigationLabels.add(navigationLabel);
             break;
  -        case "navTarget":
  +        case "navtarget":
             EpubNavigationTarget navigationTarget =
                 readNavigationTarget(navigationListChildNode);
             result.NavigationTargets.add(navigationTarget);
  
positive.code:         .where((xml.XmlNode node) => node is xml.XmlElement)
          .map((xml.XmlNode node) => node as xml.XmlElement)
          .forEach((xml.XmlElement navigationPointNode) {
        if (navigationPointNode.name.local.toLowerCase() == "navPoint") {
          EpubNavigationPoint navigationPoint =
              readNavigationPoint(navigationPointNode);
          result.Points.add(navigationPoint);
  
negative.code:         case "class":
            result.Class = attributeValue;
            break;
          case "playorder":
            result.PlayOrder = attributeValue;
            break;
        }
  