Bug 184762 BIRT Model - Enhancments to the level defintion
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
writeColumns( obj, ITableItemModel.COLUMN_SLOT );
		writeContents( obj, IListingElementModel.HEADER_SLOT,
				DesignSchemaConstants.HEADER_TAG );
		
		
		writeContents( obj, IListingElementModel.GROUP_SLOT, null );
		writeContents( obj, IListingElementModel.DETAIL_SLOT,
				DesignSchemaConstants.DETAIL_TAG );
		writeContents( obj, IListingElementModel.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, IGroupElementModel.HEADER_SLOT,
				DesignSchemaConstants.HEADER_TAG );
		writeContents( obj, IGroupElementModel.FOOTER_SLOT,
				DesignSchemaConstants.FOOTER_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 *