code: @Override
      public Object withStartElement(ElemCallback cb, Location loc)
      {
          if (mCurrToken != START_ELEMENT) {
              return null;
          }
          return cb.withStartElement(loc, getName(), 
                  mElementStack.createNonTransientNsContext(loc),
                  mAttrCollector.buildAttrOb(),
                  mStEmptyElem);
      }
docs: Method called by {@link com.ctc.wstx.evt.DefaultEventAllocator}
  to get double-indirection necessary for constructing start element
  events.
  
  @return Null, if stream does not point to start element; whatever
  callback returns otherwise.