return getUrl();
    }

    @Override
    public Map<String, Object> toSource() {
        final Map<String, Object> sourceMap = super.toSource();
        if (fields != null) {
            sourceMap.putAll(fields);
        }
        return sourceMap;
    }

    @Override
    protected void addFieldToSource(final Map<String, Object> sourceMap, final String field, final Object value) {

        return getCreatedAt();
    }

    @Override
    public Map<String, Object> toSource() {
        final Map<String, Object> sourceMap = super.toSource();
        if (fields != null) {
            sourceMap.putAll(fields);
        }
        return sourceMap;
    }

    @Override
    protected void addFieldToSource(final Map<String, Object> sourceMap, final String field, final Object value) {

    /**
     * 
     * @param key
     *            cache key
     */
    void setKey ( String key );


    /**
     * @param map
     */
    void setCacheMap ( Map<String, DfsReferralDataInternal> map );


    /**
     * Replaces the entry with key in the cache map with this referral
     */
    void replaceCache ();


    /**
     * Not exactly sure what that is all about, certainly legacy stuff

    }

    public void putAll(final Map<String, String> map) {
        params.putAll(map);
    }

    public boolean containsKey(final String key) {
        return params.containsKey(key);
    }

    public Map<String, Object> asMap() {
        return new ParamMap<>(new HashMap<>(getDataMap(params)));
    }

    protected static Map<String, Object> getDataMap(final Map<String, Object> params) {

     * {@link org.codelibs.core.collection.CollectionsUtil#isEmpty(java.util.Map)}
     * .
     */
    @Test
    public void testIsEmptyMapOfQQ() {
        HashMap<String, String> map = null;
        assertThat(CollectionsUtil.isEmpty(map), is(true));
        map = new HashMap<String, String>();
        assertThat(CollectionsUtil.isEmpty(map), is(true));
    }

    /**
     * Test method for

    public void storeQueryId(final String queryId, final List<Map<String, Object>> documentItems) {
        LaRequestUtil.getOptionalRequest().map(req -> req.getSession(false)).ifPresent(session -> {
            final FessConfig fessConfig = ComponentUtil.getFessConfig();

            final List<String> docIdList = new ArrayList<>();
            for (final Map<String, Object> map : documentItems) {

  static <K extends @Nullable Object, V extends @Nullable Object> void writeMap(
      Map<K, V> map, ObjectOutputStream stream) throws IOException {
    stream.writeInt(map.size());
    for (Map.Entry<K, V> entry : map.entrySet()) {
      stream.writeObject(entry.getKey());
      stream.writeObject(entry.getValue());
    }
  }

  /**
   * Populates a map by reading an input stream, as part of deserialization. See {@link #writeMap}

    }

    protected Optional<Map<String, String>> collectMapIfPresentOrEmpty(
            Function<O, Optional<Map<String, String>>> getter) {
        int had = 0;
        HashMap<String, String> items = new HashMap<>();
        for (O option : options) {
            Optional<Map<String, String>> up = getter.apply(option);
            if (up.isPresent()) {
                had++;

            new TestStringMapGenerator() {
              @Override
              protected Map<String, String> create(Entry<String, String>[] entries) {
                Map<String, String> map = populate(new HashMap<String, String>(), entries);
                return Collections.checkedMap(map, String.class, String.class);
              }
            })
        .named("checkedMap/HashMap")
        .withFeatures(

    default void interpolate(
            @Nonnull Map<String, String> map, @Nullable Function<String, String> callback, boolean defaultsToEmpty) {
        interpolate(map, callback, null, defaultsToEmpty);
    }

    /**
     * Interpolates the values in the given map using the provided callback function.
     *
     * @param map The map containing key-value pairs to be interpolated.