@Override
        public void serialize(JsonNode value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
            if (value instanceof NullNode) {
                gen.writeNull();
            } else if (value != null) {
                gen.writeTree(value);
            }
        }
@return An immutable {@link PathContainer} object.
aws-java-sdk-stepfunctions/src/main/java/com/amazonaws/services/stepfunctions/builder/states/PathContainer.java