code: public List<FileItemStream> items(String fieldName) {
          List<FileItemStream> filteredItems = new ArrayList<FileItemStream>();
          for (FileItemStream fis : _items) {
              if (fis.getFieldName().equals(fieldName))
                  filteredItems.add(fis);
          }
  
          return filteredItems;
      }
docs: find items with given form field name
  
  @param fieldName
  @return