Bug 249574 [Contributions] ExternalActionManager.addPropertyChangeListener() doesn't register the ListenerList
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ExternalActionManager.java
*            is assumed that the command has no parameters.
		 * @return The array of active triggers (<code>TriggerSequence</code>)
		 *         for a particular command identifier. This value is guaranteed
		 *         not to be <code>null</code>, but it may be empty.
		 * @since 3.2
		 */
		public final TriggerSequence[] getActiveBindingsFor(
				final String commandId) {
			return bindingManager.getActiveBindingsFor(commandId);
		}
		/**
		 * @see org.eclipse.jface.action.ExternalActionManager.ICallback#isAcceleratorInUse(int)
		 */
		public final boolean isAcceleratorInUse(final int accelerator) {
			final KeySequence keySequence = KeySequence
					.getInstance(SWTKeySupport
							.convertAcceleratorToKeyStroke(accelerator));
			return bindingManager.isPerfectMatch(keySequence)
					|| bindingManager.isPartialMatch(keySequence);
		}
		/**
		 * {@inheritDoc}
		 * 
		 * Calling this method with an undefined command id will generate a log
		 * message.
		 */
		public final boolean isActive(final String commandId) {
			if (commandId != null) {
				final Command command = commandManager.getCommand(commandId);
				if (!command.isDefined()