data.putValue("key2", "value2");
        data.putValue("key3", "value3");

        Set<String> keySet = data.getKeySet();
        assertNotNull(keySet);
        assertEquals(3, keySet.size());
        assertTrue(keySet.contains("key1"));
        assertTrue(keySet.contains("key2"));
        assertTrue(keySet.contains("key3"));
    }

    public void test_getKeySetEmpty() {
        // Test getKeySet on empty metadata

        assertThat(lru.get("aaa"), is("111"));
        Iterator<String> i = lru.keySet().iterator();
        assertThat(i.next(), is("bbb"));
        assertThat(i.next(), is("ccc"));
        assertThat(i.next(), is("aaa"));
        lru.put("ddd", "444");
        assertThat(lru.size(), is(3));
        assertThat(lru.get("bbb"), is(nullValue()));
        i = lru.keySet().iterator();
        assertThat(i.next(), is("ccc"));

        initParams.put("jcifs.http.insecureBasic", "true");
        initParams.put("jcifs.http.basicRealm", "TestRealm");

        when(filterConfig.getInitParameterNames()).thenReturn(Collections.enumeration(initParams.keySet()));
        when(filterConfig.getInitParameter(anyString())).thenAnswer(invocation -> initParams.get(invocation.getArgument(0)));

        assertDoesNotThrow(() -> filter.init(filterConfig));
    }

    @Test

     *
     * @param cmdList the command list to add properties to
     */
    protected void addFessConfigProperties(final List<String> cmdList) {
        System.getProperties()
                .keySet()
                .stream()
                .filter(k -> k != null && k.toString().startsWith(Constants.FESS_CONFIG_PREFIX))
                .forEach(k -> addSystemProperty(cmdList, k.toString(), null, null));
    }

        parent.putAll(m);
    }

    @Override
    public void clear() {
        parent.clear();
    }

    @Override
    public Set<K> keySet() {
        // return original keys
        return parent.keySet();
    }

    @Override
    public Collection<V> values() {
        return parent.values();
    }

    @Override
    public Set<Entry<K, V>> entrySet() {

     */
    public CaseInsensitiveSet(final int initialCapacity) {
        map = new CaseInsensitiveMap<>(initialCapacity);
    }

    @Override
    public Iterator<String> iterator() {
        return map.keySet().iterator();
    }

    @Override
    public int size() {
        return map.size();
    }

    @Override
    public boolean isEmpty() {
        return map.isEmpty();
    }

    @Override

    }

    /**
     * Returns a Set view of the keys contained in this map.
     *
     * @return a set view of the keys contained in this map
     */
    @Override
    public Set<String> keySet() {
        return parent.keySet();
    }

    /**
     * Returns a Collection view of the values contained in this map.
     *
     * @return a collection view of the values contained in this map
     */
    @Override

 * import static org.codelibs.core.collection.MultiIterator.*;
 *
 * List<String> list = ...;
 * Set<String> set = ...;
 * Map<String, Object> map = ...;
 * for (String element : iterable(list, set, map.keySet())) {
 *     ...
 * }
 * </pre>
 *
 * @author koichik
 * @param <E> the element type
 */
public class MultiIterator<E> implements Iterator<E> {

    /** Array of {@link Iterator}s. */

    public String toString() {
        StringBuilder ret = new StringBuilder().append(proto).append(":").append(server).append("[").append(endpoint);
        if (options != null) {
            final Iterator iter = options.keySet().iterator();
            while (iter.hasNext()) {
                final Object key = iter.next();
                final Object val = options.get(key);
                ret.append(",").append(key).append("=").append(val);

        initParams.put("jcifs.http.insecureBasic", "true");
        initParams.put("jcifs.http.basicRealm", "TestRealm");

        lenient().when(servletConfig.getInitParameterNames()).thenReturn(Collections.enumeration(initParams.keySet()));
        lenient().when(servletConfig.getInitParameter(anyString())).thenAnswer(invocation -> initParams.get(invocation.getArgument(0)));

        // Mock HTTP method for request - this is required for HttpServlet.service()