setStringProperty( IGroupElementModel.TOC_PROP, expression );
if ( StringUtil.isEmpty( expression ) ) { setProperty( IGroupElementModel.TOC_PROP, null ); return; } TOCHandle tocHandle = getTOC( ); if ( tocHandle == null ) { TOC toc = StructureFactory.createTOC( expression ); addTOC( toc ); } else { tocHandle.setExpression( expression ); }
	public void setTocExpression( String expression ) throws SemanticException	{		setStringProperty( IGroupElementModel.TOC_PROP, expression );	}