code: public static boolean getHandleErrorWithFatalErrorPageFactory() {
  		Boolean parameterValue = get().getBoolean(HANDLE_ERROR_WITH_FATAL_PAGE_FACTORY, null);
  		if (parameterValue != null) {
  			return parameterValue;
  		}
  
  		// fall-back to the old parameter value if the new value is not set.
  		return get().getBoolean(HANDLE_ERROR_WITH_FATAL_PAGE_FACTORY_DEPRECATED, false);
  	}
docs: The flag indicating whether to handle an error with a fatal error page factory.
  
  @return the new parameter value if set, else the old parameter value if set, or false if neither set.