code: @NotNull
      public static <K, V> Stream<Map.Entry<K, V>> ofNullable(@Nullable Map<K, V> map) {
          return (map == null) ? Stream.<Map.Entry<K, V>>empty() : Stream.of(map);
      }
docs: If specified map is null, returns an empty {@code Stream},
  otherwise returns a {@code Stream} containing entries of this map.
  
  @param <K> the type of map keys
  @param <V> the type of map values
  @param map  the map with elements to be passed to stream
  @return the new stream
  @since 1.1.9