code: public static PageFlowController getNestingPageFlow( HttpServletRequest request, ServletContext servletContext )
      {
          PageFlowStack jpfStack = PageFlowStack.get( request, servletContext, false );
          
          if ( jpfStack != null && ! jpfStack.isEmpty() )
          {
              PageFlowController top = jpfStack.peek().getPageFlow();
              return top;
          }
          
          return null;
      }
docs: Get the {@link PageFlowController} that is nesting the current one.
  
  @param request the current HttpServletRequest.
  @param servletContext the current ServletContext.
  @return the nesting {@link PageFlowController}, or <code>null</code> if the current one
  is not being nested.