Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ComplexPropertyCommand.java
throws PropertyValueException
	{
		assert ref != null;
		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 );
		if ( posn < 0 || posn >= list.size( ) )
			throw new IndexOutOfBoundsException(
					"Posn: " + posn + ", List Size: " + list.size( ) ); 
		PropertyDefn memberDefn = ref.getMemberDefn( );
		if ( memberDefn != null
				&& memberDefn.getTypeCode( ) == IPropertyType.LIST_TYPE )
			doRemoveItem( ref, posn );
		else
			doRemoveItem( new CachedMemberRef( ref, posn ) );
	}
	/**
	 * Removes an item from a structure list.
	 * <ul>
	 * <li>The element must exist in the current effective value for the list.
	 * This means the list must be set on this element or a ancestor element.
	 * </li>
	 * <li>If the property is set on this element, then the element is simply
	 * removed.</li>