code: @Override
      public void onComponentTag(final Component _component,
                                 final ComponentTag _tag)
      {
          super.onComponentTag(_component, _tag);
  
          if (this.type == DnDBehavior.BehaviorType.ITEM) {
              String value = "dojoDndItem ";
              if (_tag.getAttribute("class") != null) {
                  value += _tag.getAttribute("class");
              }
              _tag.put("dndType", this.dndType);
              _tag.put("class", value);
          }
      }
docs: The tag of the component must be altered, so that the dojo dnd will be rendered.
  
  @see org.apache.wicket.behavior.AbstractBehavior#onComponentTag(org.apache.wicket.Component,
  org.apache.wicket.markup.ComponentTag)
  @param _component Component
  @param _tag tag to edit