code: public void init(Convert converter, JComponent component1, JComponent component2)
      {
          m_converter = converter;
          this.setBorder(null);
          this.setOpaque(false);
          
          this.setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
          if (component1 != null)
              this.addComponent(component1, true);
          
          if (component2 != null)
              this.addComponent(component2, true);
      }
docs: Creates new JCalendarDualField.
  @param The field this component is tied to.