docs: public JComponent addScreenControl(Container parent, Converter fieldInfo)
      {
          JComponent component = this.createScreenComponent(fieldInfo);
          if (component instanceof ScreenComponent)
              if (((ScreenComponent)component).getConverter() != null)
                  fieldInfo = (Converter)((ScreenComponent)component).getConverter();
          this.addScreenComponent(parent, fieldInfo, component);
          return component;
      }