code: public void addZone(String id, Component zone, String constraints) {
          // is there already a zone with this id?
          Component previousZone = getZone(id);
          if (previousZone != null) {
              remove(previousZone);
              idToZones.remove(id);
          }
  
          if (zone instanceof JComponent) {
              JComponent jc = (JComponent) zone;
              if (jc.getBorder() == null || jc.getBorder() instanceof UIResource) {
                  if (jc instanceof JLabel) {
                      jc.setBorder(
                              new CompoundBorder(zoneBorder, new EmptyBorder(0, 2, 0, 2)));
                      ((JLabel) jc).setText(" ");
                  } else {
                      jc.setBorder(zoneBorder);
                  }
              }
          }
  
          add(zone, constraints);
          idToZones.put(id, zone);
      }
docs: Adds a new zone in the StatusBar.
  
  @param id
  @param zone
  @param constraints one of the constraint support by the
  {@link com.l2fprod.common.swing.PercentLayout}