Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ComplexPropertyCommand.java
* <li>If the property is set on an ancestor element, then the inherited
	 * list is first <strong>copied </strong> into this element. Then, the copy
	 * of the target item is removed from the copy of the list.</li>
	 * </ul>
	 * 
	 * @param ref
	 *            the structure list reference
	 * @param structure
	 *            the item to remove
	 * @throws PropertyValueException
	 *             if the item to remove is not found.
	 */
	public void removeItem( MemberRef ref, IStructure structure )
			throws PropertyValueException
	{
		PropertyDefn propDefn = ref.getPropDefn( );
		assert propDefn != null;
		assertExtendedElement( module, element, propDefn );
		checkListMemberRef( ref );
		List list = ref.getList( module, element );
		if ( list == null )
			throw new PropertyValueException( element, ref.getPropDefn( ),
					null,
					PropertyValueException.DESIGN_EXCEPTION_ITEM_NOT_FOUND );
		int posn = list.indexOf( structure );
		if ( posn == -1 )
			throw new PropertyValueException( element, ref.getPropDefn( )
					.getName( ), null,
					PropertyValueException.DESIGN_EXCEPTION_ITEM_NOT_FOUND );
		doRemoveItem( new CachedMemberRef( ref, posn ) );