Bug 155943 "Restore Properties" is always enabled for extended chart
Steps to reproduce: 1.New a report, includes a library, extends lib.chart 2.Choose the chart Expected result: "Restore Properties" is disabled untill set/change any local properties for the chart Actual result: "Restore Properties" is always enabled
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
writeContents( obj, TableItem.HEADER_SLOT,
				DesignSchemaConstants.HEADER_TAG );
		
		
		writeContents( obj, TableItem.GROUP_SLOT, null );
		writeContents( obj, TableItem.DETAIL_SLOT,
				DesignSchemaConstants.DETAIL_TAG );
		writeContents( obj, TableItem.FOOTER_SLOT,
				DesignSchemaConstants.FOOTER_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.design.elements.DesignVisitor#visitTableGroup(org.eclipse.birt.report.model.design.elements.TableGroup)
	 */
	public void visitTableGroup( TableGroup obj )
	{
		writer.startElement( DesignSchemaConstants.GROUP_TAG );
		super.visitTableGroup( obj );
		writeContents( obj, TableGroup.HEADER_SLOT,
				DesignSchemaConstants.HEADER_TAG );
		writeContents( obj, TableGroup.FOOTER_SLOT,
				DesignSchemaConstants.FOOTER_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.design.elements.DesignVisitor#visitColumn(org.eclipse.birt.report.model.design.elements.TableColumn)