docs: public static Map<String, Attachment> findNewAttachments(Map<String, ? extends Attachment> attachments) {
          Map<String, Attachment> newAttachments = new HashMap<String, Attachment>();
          for (Map.Entry<String, ? extends Attachment> a : attachments.entrySet()) {
              if (!(a instanceof SavedAttachment)) {
                  newAttachments.put(a.getKey(), a.getValue());
              }
          }
          return newAttachments;
      }