@ThreadConfined(type = ThreadType.UI)
private final Map<Long, DrawableCell> cellMap = new HashMap<>();
public GroupPane(ImageAnalyzerController controller) {
this.controller = controller;
nextGroupAction = new NextUnseenGroup(controller);
backAction = new Back(controller);
forwardAction = new Forward(controller);
FXMLConstructor.construct(this, "GroupPane.fxml");
}