private static void bindMultipartVariable(Map<String, Object> variables, List<String> operationsPaths,
                                              @Nullable List<MultipartFile> multipartFiles) {
        if (multipartFiles == null || multipartFiles.isEmpty()) {
            return;
        }
        final MultipartFile multipartFile = multipartFiles.get(0);
        for (String objectPath : operationsPaths) {
            MultipartVariableMapper.mapVariable(objectPath, variables, multipartFile);
        }
    }
Should not use {@link JacksonUtil#newDefaultObjectMapper()} that will convert a JSON object into
`scala.Map` if a `jackson-module-scala` module is registered.
graphql-protocol/src/main/java/com/linecorp/armeria/server/graphql/protocol/AbstractGraphqlService.java