final ActionForm form = new ActionForm();
        assertNull(form.replaceAliases);
        assertNull(form.resetDictionaries);
        // numberOfShardsForDoc and autoExpandReplicasForDoc have defaults from FessConfig
        assertNotNull(form.numberOfShardsForDoc);
        assertNotNull(form.autoExpandReplicasForDoc);
        assertNull(form.loadBulkData);
        // rebuildConfigIndex defaults to Constants.ON

     * The flag to reset dictionaries.
     */
    @Size(max = 10)
    public String resetDictionaries;

    /**
     * The number of shards for doc.
     */
    @Size(max = 10)
    public String numberOfShardsForDoc = ComponentUtil.getFessConfig().getIndexNumberOfShards();

    /**
     * The auto expand replicas for doc.
     */
    @Size(max = 10)