src/main/java/org/jboss/util/ThrowableHandler.java
/**
    * Add a ThrowableListener to the listener list.  Listener is added only
    * if if it is not already in the list.
    *
    * @param listener   ThrowableListener to add to the list.
    */
Add a ThrowableListener to the listener list.  Listener is added only
if if it is not already in the list.

@param listener   ThrowableListener to add to the list.
Add a ThrowableListener to the listener list . Listener is added only if if it is not already in the list . @param listener ThrowableListener to add to the list .
public static void addThrowableListener(ThrowableListener listener) {
      if (!listeners.contains(listener)) {
         listeners.add(listener);
      }
   }
public static void addThrowableListener ( ThrowableListener listener ) { if ( ! listeners . contains ( listener ) ) { listeners . add ( listener ) ; } }
Add a ThrowableListener to the listener list.
Add a ThrowableListener to the listener list .
// only add the listener if it isn't already in the list