@Nonnull
    public static <K, V> Sink<Entry<K, V>> map(@Nonnull String mapName) {
        return map(mapName, Entry::getKey, Entry::getValue);
    }
@Test
    public void map_byRef() {
        // Given
        List<Integer> input = sequence(itemCount);
        putToBatchSrcMap(input);
        IMap<String, Integer> sinkMap = hz().getMap(sinkName);

        // When
        Sink<Entry<String, Integer>> sink = Sinks.map(sinkMap);

        // Then
        p.readFrom(Sources.<String, Integer>map(srcName)).writeTo(sink);
        execute();
        List<Entry<String, Integer>> expected = input.stream()
                                                     .map(i -> entry(String.valueOf(i), i))
                                                     .collect(toList());
        Set<Entry<String, Integer>> actual = sinkMap.entrySet();
        assertEquals(expected.size(), actual.size());
        expected.forEach(entry -> assertTrue(actual.contains(entry)));
    }