code: protected Iterator<FormItem> uploadedFiles(String encoding, long maxFileSize) {
          List<FormItem> fileItems = new ArrayList<>();
          for(FormItem item : multipartFormItems(encoding, maxFileSize)) {
              if (item.isFile()) {
                  fileItems.add(item);
              }
          }
          return fileItems.iterator();
      }
docs: Returns a collection of uploaded files from a multi-part port request.
  
  @param encoding specifies the character encoding to be used when reading the headers of individual part.
  When not specified, or null, the request encoding is used. If that is also not specified, or null,
  the platform default encoding is used.
  @param maxFileSize maximum file size in the upload in bytes. -1 indicates no limit.
  
  @return a collection of uploaded files from a multi-part port request.