code: @Override
      protected void initValidation() throws XMLStreamException
      {
          if (hasConfigFlags(CFG_VALIDATE_AGAINST_DTD)
              && !mDtdValidatorSet) {
              /* It's ok to miss it, but it may not be what caller wants. Either
               * way, let's pass the info and continue
               */
              reportProblem(null, ErrorConsts.WT_DT_DECL, ErrorConsts.W_MISSING_DTD, null, null);
          }
      }
docs: Method called right before handling the root element, by the base
  class. This allows for some initialization and checks to be done
  (not including ones that need access to actual element name)