code: public static SharedFlowController getSharedFlow( String sharedFlowClassName, HttpServletRequest request,
                                                        ServletContext servletContext )
      {
          StorageHandler sh = Handlers.get( servletContext ).getStorageHandler();
          HttpServletRequest unwrappedRequest = unwrapMultipart( request );
          RequestContext rc = new RequestContext( unwrappedRequest, null );
          String attrName = ScopedServletUtils.getScopedSessionAttrName(InternalConstants.SHARED_FLOW_ATTR_PREFIX
                                                                        + sharedFlowClassName, request);
          SharedFlowController sf = (SharedFlowController) sh.getAttribute(rc, attrName);
          if (sf != null) {
              sf.reinitializeIfNecessary(request, null, servletContext);
          }
          return sf;
      }
docs: Get the shared flow with the given class name.
  
  @param sharedFlowClassName the class name of the shared flow to retrieve.
  @param request the current HttpServletRequest.
  @return the {@link SharedFlowController} of the given class name which is stored in the user session.