Bug 188829 Move the item ,the trans of the model don't close.
1:New report design. 2:Add a Embedded image. 3:Add another imge , then drag the second imge to the first position. 4:Change the size of the first image. Expected: Image change the size. Now: Image size don't change.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/command/ContentCommandTest.java
* <li>Drop and detach referenceable element
	 * <li>Drop referenceable element
	 * </ul>
	 * 
	 * @throws Exception
	 */
	public void testElementReferenceAfterDeletionAndDetachment( )
			throws Exception
	{
		
		createDataSourceAndDataSet( );
		DataSourceHandle dataSourceHandle = designHandle
				.findDataSource( "dataSource" );
		DataSetHandle dataSetHandle = designHandle.findDataSet( "dataSet" );
		dataSourceHandle.dropAndClear( );
		assertEquals( null, dataSetHandle.getDataSourceName( ) );
		assertEquals( null, dataSetHandle.getDataSource( ) );
		Iterator iter = dataSourceHandle.clientsIterator( );
		assertEquals( false, iter.hasNext( ) );
		designHandle.getCommandStack( ).undo( );
		assertEquals( dataSourceHandle.getName( ), dataSetHandle
				.getDataSourceName( ) );
		assertEquals( dataSourceHandle, dataSetHandle.getDataSource( ) );
		iter = dataSourceHandle.clientsIterator( );
		assertEquals( true, iter.hasNext( ) );
		
		createDataSourceAndDataSet( );
		dataSourceHandle = designHandle.findDataSource( "dataSource" );
		dataSetHandle = designHandle.findDataSet( "dataSet" );
		dataSourceHandle.drop( );