docs: public MultipartResourceRequest resolveMultipart(final ResourceRequest request) throws MultipartException {
          Assert.notNull(request, "Request must not be null");
          if (this.resolveLazily) {
              return new DefaultMultipartResourceRequest(request) {
                  @Override
                  protected void initializeMultipart() {
                      MultipartParsingResult parsingResult = parseRequest(request);
                      setMultipartFiles(parsingResult.getMultipartFiles());
                      setMultipartParameters(parsingResult.getMultipartParameters());
                      setMultipartParameterContentTypes(parsingResult.getMultipartParameterContentTypes());
                  }
              };
          } else {
              MultipartParsingResult parsingResult = parseRequest(request);
              return new DefaultMultipartResourceRequest(request, parsingResult.getMultipartFiles(),
                      parsingResult.getMultipartParameters(), parsingResult.getMultipartParameterContentTypes());
          }
      }