Bug 136270 Group's data binding column can only be used by the group itself
If you add some data binding columns to a group, these columns can only be used by this group itself. It should has a way to make the child can use the parent group's data binding column.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
/**
	 * @deprecated
	 */
	public static List getDataSets( )
	{
		return SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( )
				.getVisibleDataSets( );
	}
	public static Iterator getThemes( )
	{
		return getThemes( new AlphabeticallyComparator( ) );
	}
	private static Iterator getThemes( AlphabeticallyComparator comparator )
	{
		List themes = SessionHandleAdapter.getInstance( )
				.getReportDesignHandle( )
				.getVisibleThemes( IAccessControl.DIRECTLY_INCLUDED_LEVEL );
		Object[] themesArray = themes.toArray( );
		if ( comparator != null )
		{
			Arrays.sort( themesArray, comparator );
		}
		return Arrays.asList( themesArray ).iterator( );
	}
	/**
	 * Generates GroupElementHandle for given model list.
	 * 
	 * @param modelList
	 * @return