code: public VariableInfo[] getVariableInfo(TagData data) {
         VariableInfo[] result = null;
         TagExtraInfo tei = getTagExtraInfo();
         if (tei != null) {
  	   result = tei.getVariableInfo( data );
         }
         return result;
     }
docs: Information on the scripting objects created by this tag at runtime.
  This is a convenience method on the associated TagExtraInfo class.
  
  @param data TagData describing this action.
  @return if a TagExtraInfo object is associated with this TagInfo, the
  result of getTagExtraInfo().getVariableInfo( data ), otherwise
  null.