anchor.diff: -import 'dart:collection';
  -
   import 'entities/entity_mapping.dart';
   import 'nodes/attribute.dart';
   import 'nodes/cdata.dart';
  
positive.code:       bool isSelfClosing = true,
        Object? nest}) {
      final element = NodeBuilder();
      _stack.addLast(element);
      namespaces.forEach(this.namespace);
      attributes.forEach(attribute);
      if (nest != null) {
  
negative.code:     _stack.clear();
      final node = NodeBuilder();
      node.namespaces[ns.xmlUri] = NamespaceData.xmlData;
      _stack.add(node);
    }
  
    // Internal method to build a name.
  