code: public boolean hasApplicableHiddenWarnings() {
          UpdateSiteWarningsConfiguration configuration = ExtensionList.lookupSingleton(UpdateSiteWarningsConfiguration.class);
          return getActiveWarnings().size() < configuration.getApplicableWarnings().size();
      }
docs: Returns true iff there are applicable but ignored (i.e. hidden) warnings.
  
  @return true iff there are applicable but ignored (i.e. hidden) warnings.