Bug 183918 get relative file path of linkage library
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ComplexPropertyCommand.java
* 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>
	 * <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
	{
		checkAllowedOperation( );
		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( ),