code: protected final void verifyWriteCData()
          throws XMLStreamException
      {
          // Not legal outside main element tree:
          if (mCheckStructure) {
              if (inPrologOrEpilog()) {
                  reportNwfStructure(ErrorConsts.WERR_PROLOG_CDATA);
              }
          }
          // 08-Dec-2005, TSa: validator-based validation?
          if (mVldContent <= XMLValidator.CONTENT_ALLOW_WS) {
              // there's no ignorable white space CDATA...
              reportInvalidContent(CDATA);
          }
      }
docs: /*
  /////////////////////////////////////////////////////////
  Package methods, validation
  /////////////////////////////////////////////////////////