Bug 153038 NPE when delete master page content in old report design.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/editparts/ListEditPart.java
public void refreshChildren( )
	{
		super.refreshChildren( );
		List list = getChildren( );
		int size = list.size( );
		for ( int i = 0; i < size; i++ )
		{
			( (ListBandEditPart) list.get( i ) ).refreshChildren( );
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.editparts.AbstractGraphicalEditPart#createFigure()
	 */
	protected IFigure createFigure( )
	{
		ListFigure figure = new ListFigure( );
		figure.setOpaque( false );
		return figure;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.designer.internal.ui.editors.schematic.editparts.ReportElementEditPart#getModelChildren()
	 */
	protected List getModelChildren( )
	{
		return getListHandleAdapt( ).getChildren( );
	}