code: public static synchronized void multipart(HttpString method, String url, HttpConsumer<MultipartExchange> endpoint, long maxSize) {
          checkStarted();
          instance().endpoints.add(HandlerUtil.multipart(method, url, endpoint, instance().exceptionMapper, maxSize));
      }
docs: Define a endpoint that accepts a specialized {@link Exchange} to handle multipart requests. The data is parsed eagerly.
  
  @param method   The Http method for this endpoint.
  @param url      The relative URL to be map this endpoint.
  @param endpoint The endpoint handler
  @param maxSize  The maximum size for the request body