code: protected static List<Stage> findPopups() throws QTasteTestFailException {
          //find all popups
          List<Stage> popupFound = new ArrayList<>();
          for (Stage stage : getStages()) {
              Parent root = stage.getScene().getRoot();
              if (isAPopup(stage)) {
                  //it's maybe a popup... a popup is modal and not resizable and has a DialogPane root
                  DialogPane dialog = (DialogPane) root;
                  LOGGER.trace("Find a popup with the title '" + stage.getTitle() + "'.");
                  popupFound.add(stage);
              }
          }
          return popupFound;
      }
docs: Finds all popups. A Component is a popup if it's a DialogPane, modal and not resizable.
  
  @return the list of all found popups.