public static <K, V> MapStream<K, V> of(Map.Entry<K, V> entry) {
        return new MapStream<>(requireNonNull(Stream.of(entry)));
    }
Constructs a new {@code MapStream} from a single entry.

@param <K>    key type
@param <V>    value type
@param entry  the entry
@return       created {@code MapStream}
common-parent/mapstream/src/main/java/com/speedment/common/mapstream/MapStream.java