Bug 183918 get relative file path of linkage library
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/ComplexPropertyCommand.java
*             <code>(index &lt; 0 || index &gt;= list.size())</code>.
	 */
	public void removeItem( ElementPropertyDefn prop, int posn )
			throws PropertyValueException
	{
		assert prop != null;
		checkAllowedOperation( );
		
		assertExtendedElement( module, element, prop );
		checkListProperty( prop );
		List list = element.getListProperty( module, prop.getName( ) );
		if ( list == null )
			throw new PropertyValueException( element, prop.getName( ), null,
					PropertyValueException.DESIGN_EXCEPTION_ITEM_NOT_FOUND );
		if ( posn < 0 || posn >= list.size( ) )
			throw new IndexOutOfBoundsException(
					"Posn: " + posn + ", List Size: " + list.size( ) ); 
		Object obj = list.get( posn );
		doRemoveItem( prop, posn, obj );
	}
	/**
	 * Removes structure from structure list.
	 * 
	 * @param structRef
	 *            reference to the item to remove
	 */
	private void doRemoveItem( ElementPropertyDefn prop, int posn, Object item )
	{
		String label = ModelMessages
				.getMessage( MessageConstants.REMOVE_ITEM_MESSAGE );