code: private void initGraphics() {
          // Set initial size
          if (Double.compare(gauge.getPrefWidth(), 0.0) <= 0 || Double.compare(gauge.getPrefHeight(), 0.0) <= 0 ||
              Double.compare(gauge.getWidth(), 0.0) <= 0 || Double.compare(gauge.getHeight(), 0.0) <= 0) {
              if (gauge.getPrefWidth() > 0 && gauge.getPrefHeight() > 0) {
                  gauge.setPrefSize(gauge.getPrefWidth(), gauge.getPrefHeight());
              } else {
                  gauge.setPrefSize(PREFERRED_WIDTH, PREFERRED_HEIGHT);
              }
          }
  
          for (int i = 0 ; i < 12 ; i++) {
              Region bar = new Region();
              bar.setPrefSize(20, 20 + (i * 4));
              bars[i] = bar;
          }
  
          pane = new HBox(bars);
          pane.setSpacing(PREFERRED_WIDTH * 0.01960784);
          pane.setAlignment(Pos.BOTTOM_CENTER);
          pane.setFillHeight(false);
          pane.setBackground(new Background(new BackgroundFill(backgroundPaint, new CornerRadii(1024), Insets.EMPTY)));
          pane.setBorder(new Border(new BorderStroke(borderPaint, BorderStrokeStyle.SOLID, new CornerRadii(1024), new BorderWidths(borderWidth))));
  
          getChildren().setAll(pane);
      }
docs: ******************** Initialization ************************************