private void writeAttributeAsList(
     XMLExtendedStreamWriter writer,
     final ModelNode node,
     final ListAttributeDefinition modelAttribute)
     throws XMLStreamException {
   if (modelAttribute.isMarshallable(node, false)) {
     StringBuilder sb = new StringBuilder();
     Iterator<ModelNode> iter = node.get(modelAttribute.getName()).asList().iterator();
     if (iter.hasNext()) {
       sb.append(iter.next().asString());
       while (iter.hasNext()) {
         sb.append(" ").append(iter.next().asString());
       }
       writer.writeAttribute(modelAttribute.getXmlName(), sb.toString());
     }
   }
 }
 public Builder(ListAttributeDefinition basis) {
   super(basis);
   this.elementValidator = basis.getElementValidator();
 }