Bug 146481 Name is not necessary for extended element
Steps to reproduce: 1.New a label named "label" in library 2.New a report, extend lib.label Expected result: No name for the extended label Actual result: "label" is added as the name of label in report. It's not reasonable because "Restore Properties" is enabled even without properties change.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/EmptyGroupElementHandle.java
return Collections.EMPTY_LIST;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#visiblePropertyIterator()
	 */
	
	public Iterator visiblePropertyIterator( )
	{
		return new GroupPropertyIterator( Collections.EMPTY_LIST );
	}
	/* (non-Javadoc)
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#isPropertyVisible(java.lang.String)
	 */
	
	protected boolean isPropertyVisible( String propName )
	{
		return false;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#clearLocalProperties()
	 */
	
	public void clearLocalProperties( ) throws SemanticException
	{
		
	}
	/* (non-Javadoc)
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#isExtendedElements()
	 */