code: public static <M extends Map<?, ?>> MapJsonSerializer<M, ?, ?> newInstance( KeySerializer<?> keySerializer, JsonSerializer<?>
              valueSerializer ) {
          return new MapJsonSerializer( keySerializer, valueSerializer );
      }
docs: <p>newInstance</p>
  
  @param keySerializer {@link KeySerializer} used to serialize the keys.
  @param valueSerializer {@link JsonSerializer} used to serialize the values.
  @return a new instance of {@link MapJsonSerializer}
  @param <M> a M object.