docs: public static <T> void mergeFrom(XMLStreamReader parser, T message, Schema<T> schema)
              throws IOException, XMLStreamException, XmlInputException
      {
          // final String simpleName = schema.messageName();
  
          if (parser.nextTag() != START_ELEMENT ||
                  !schema.messageName().equals(parser.getLocalName()))
          {
              throw new XmlInputException("Expected token START_ELEMENT: " + schema.messageName());
          }
  
          if (parser.nextTag() == END_ELEMENT)
          {
              // if(!simpleName.equals(parser.getLocalName()))
              // throw new XmlInputException("Expecting token END_ELEMENT: " + simpleName);
  
              // empty message;
              return;
          }
  
          schema.mergeFrom(new XmlInput(parser), message);
  
          // if(!simpleName.equals(parser.getLocalName()))
          // throw new XmlInputException("Expecting token END_ELEMENT: " + simpleName);
      }