Bug 145520 Group name will not show up in group list if the group use default name and key expression has no value
Description: Group name will not show up in group list if key expression has no value. Steps to reproduce: 1. Insert a table into report, bind it to a data set 2. Switch to property editor -> groups 3. Click on add button to open new group dialog, then press ok button Expected result: A new group with default name will be added to group list Actual result: A new group is added to group list, but without group name. But when let group tab lost focus and get focus again, you can see the group name.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
*/
	public boolean removeDisposeListener( IDisposeListener listener )
	{
		if ( disposeListeners == null )
			return false;
		return disposeListeners.remove( listener );
	}
	/**
	 * Broadcasts the dispose event to the dispose listeners.
	 * 
	 * @param event
	 *            the dispose event
	 */
	public void broadcastDisposeEvent( DisposeEvent event )
	{
		if ( disposeListeners == null || disposeListeners.isEmpty( ) )
			return;
		List temp = new ArrayList( disposeListeners );
		Iterator iter = temp.iterator( );
		while ( iter.hasNext( ) )
		{
			IDisposeListener listener = (IDisposeListener) iter.next( );
			listener.moduleDisposed( (ModuleHandle) getHandle( this ), event );
		}
	}
	/**
	 * Return a list of user-defined message keys. The list contained resource
	 * keys defined in the report itself and the keys defined in the referenced
	 * message files for the current thread's locale. The list returned contains
	 * no duplicate keys.