code: @Override
      public Object getRootContext() throws BadMessageFormatMatchingException {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.entry(this, tc, "getRootContext");
  
          // Just call the subclass's method to obtain the DOM Document which
          // represents the payload.
          Object result;
          try {
              result = getPayloadDocument();
          } catch (Exception e) {
              FFDCFilter.processException(e, "com.ibm.ws.sib.mfp.impl.JsApiMessageImpl.getRootContext", "921");
              result = null;
          }
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              SibTr.exit(this, tc, "getRootContext", result);
          return result;
      }
docs: /*
  Provided for use in XPath support where the MatchSpace calls MFP
  in order to retrieve the top most Node in a DOM tree.
  
  Javadoc description supplied by MatchSpaceKey interface.