Bug 194843 Cross tab Cube - Cannot delete a dimension using the cube builder
- Open the attached report design - Delete the "Region" group. Current behavior - Does now allow me to delete the group.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/command/ContentCommandTest.java
* <li>After undo and redo both of the reference status and the element
	 * status can be recovered.
	 * </ul>
	 * 
	 * @throws Exception
	 *             if any exception
	 */
	public void testNormalCaseUndoAndRedo( ) throws Exception
	{
		DesignElementHandle contentHandle = factory.newFreeForm( null );
		ActivityStack as = design.getActivityStack( );
		containerHandle.getSlot( 0 ).add( contentHandle );
		Object obj = container.getSlot( 0 ).getContent( 0 );
		assertEquals( contentHandle.getElement( ), obj );
		
		assertEquals( container, contentHandle.getContainer( ) );
		
		assertFalse( as.canRedo( ) );
		assertTrue( as.canUndo( ) );
		as.undo( );
		assertEquals( 0, container.getSlot( 0 ).getCount( ) );
		
		assertTrue( as.canRedo( ) );
		as.redo( );
		obj = container.getSlot( 0 ).getContent( 0 );
		assertEquals( contentHandle.getElement( ), obj );
		containerHandle.getSlot( 0 ).dropAndClear( 0 );
		assertTrue( container.getSlot( 0 ).getCount( ) == 0 );
		
		assertNull( contentHandle.getContainer( ) );