docs: public String getUploadHook(CmsObject cms, String uploadFolder) {
  
          if (m_postUploadHandler != null) {
              return m_postUploadHandler.getUploadHook(cms, uploadFolder);
          }
          I_CmsDialogHandler handler = getDialogHandler(CmsDialogSelector.DIALOG_PROPERTY);
          if ((handler != null) && (handler instanceof I_CmsPostUploadDialogHandler)) {
              return ((I_CmsPostUploadDialogHandler)handler).getUploadHook(cms, uploadFolder);
          } else {
              return null;
          }
      }