/**
  * Handles the focusLost event by invoking the focusLost methods on listener-a and listener-b.
  *
  * @param e the focus event
  */
 public void focusLost(FocusEvent e) {
   ((FocusListener) a).focusLost(e);
   ((FocusListener) b).focusLost(e);
 }
 /**
  * Handles the focusGained event by invoking the focusGained methods on listener-a and listener-b.
  *
  * @param e the focus event
  */
 public void focusGained(FocusEvent e) {
   ((FocusListener) a).focusGained(e);
   ((FocusListener) b).focusGained(e);
 }