Bug 153038 NPE when delete master page content in old report design.
UI/org.eclipse.birt.report.designer.ui.editors.schematic/src/org/eclipse/birt/report/designer/internal/ui/editors/layout/ReportEditorWithPalette.java
*      org.eclipse.ui.IEditorInput)
	 */
	public void init( IEditorSite site, IEditorInput input )
			throws PartInitException
	{
		super.init( site, input );
		if ( getModel( ) == null )
		{
			throw new PartInitException( DLG_ERROR_OPEN_ERROR_MSG );
		}
	}
	/**
	 * Get report modulehandle. if model havn't been set, get the editor input
	 * modulehandle.
	 * 
	 * @return
	 */
	protected ModuleHandle getModel( )
	{
		if(model == null)
		{
			IReportProvider reportProvider = getProvider( );
			model = reportProvider.getReportModuleHandle( getEditorInput( ) );
		}
		
		return model;
	}
	/**
	 * Set the report model
	 *