*       channel have their own file descriptors. Generally this only happens when both channels
   *       are files or sockets. This performs zero copies - the bytes never enter userspace.
   *   <li>Use mmap(2) or equivalent. Requires that either the input channel or the output channel
   *       have file descriptors. Bytes are copied from the file into a kernel buffer, then directly

Shinsuke Sugaya <******@****.***> 1755149504 +0900

        assertThat(map.containsKey("3"), is(not(true)));
        map.put("3", null);
        assertThat(map.containsKey("3"), is(true));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIndexOf() throws Exception {
        assertThat(map.indexOf("test"), is(1));
        assertThat(map.indexOf(null), is(0));
        assertThat(map.indexOf("test3"), is(-1));

        map.putAll(m);
        assertThat(map.get("THREE"), is("3"));
        assertThat(map.get("FOUR"), is("4"));
        assertThat(map.size(), is(4));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testPerformance() throws Exception {
        for (int j = 0; j < 3; ++j) {
            final int num = 100000;
            final Map<String, String> hmap = new HashMap<String, String>();

	}

	info.StatsSummary = make(map[string]madmin.SRSiteSummary, len(c.state.Peers))
	info.BucketStats = make(map[string]map[string]srBucketStatsSummary)
	info.PolicyStats = make(map[string]map[string]srPolicyStatsSummary)
	info.UserStats = make(map[string]map[string]srUserStatsSummary)
	info.GroupStats = make(map[string]map[string]srGroupStatsSummary)
	info.ILMExpiryRulesStats = make(map[string]map[string]srILMExpiryRuleStatsSummary)

 *
 * Map<String, Integer> map = map("a", 1).$("b", 2).$("c", 3).$();
 * </pre>
 *
 * @author koichik
 * @param <K> the key type of the {@literal Map}
 * @param <V> the value type of the {@literal Map}
 */
public class Maps<K, V> {

    /** The target <code>Map</code> to be created. */
    protected Map<K, V> map;

    /**

        Map<String, Object> parentMap = new LinkedHashMap<>();
        DocMap docMap = new DocMap(parentMap);

        docMap.put("c_key", "value_c");
        docMap.put("a_key", "value_a");
        docMap.put("lang", "en");
        docMap.put("b_key", "value_b");

        Set<Map.Entry<String, Object>> entrySet = docMap.entrySet();
        String[] keys = entrySet.stream().map(Map.Entry::getKey).toArray(String[]::new);

        final AtomicReference<String> sentIndex = new AtomicReference<>();
        final List<Map<String, Object>> sentDocList = new ArrayList<>();
        final SearchEngineClient client = new SearchEngineClient() {
            @Override
            public BulkResponse addAll(final String index, final List<Map<String, Object>> docList,
                    final BiConsumer<Map<String, Object>, IndexRequestBuilder> options) {
                sentIndex.set(index);

        return idList;
    }

    protected static List<Map<String, Object>> readJobLog(final String namePrefix) {
        final List<Map<String, Object>> logList = readLogItems("joblog");
        final List<Map<String, Object>> resList = new ArrayList<>();
        for (Map<String, Object> elem : logList) {

    }

    static <K, V> Map<K, V> copy(Map<K, V> map) {
        if (map == null) {
            return emptyMap();
        } else if (map instanceof AbstractImmutableMap) {
            return map;
        } else {
            switch (map.size()) {
                case 0:
                    return emptyMap();
                case 1:
                    Map.Entry<K, V> entry = map.entrySet().iterator().next();