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/src/org/eclipse/birt/report/model/command/ContentCommand.java
* @param element
	 *            the element to insert
	 * @throws NameException
	 *             if name duplicate occurs
	 * @throws ContentException
	 *             the slot cannot contain the given element.
	 */
	private void checkContainmentContext( DesignElement content )
			throws NameException, ContentException
	{
		List errors = focus.checkContainmentContext( module, content );
		if ( !errors.isEmpty( ) )
		{
			SemanticException e = (SemanticException) errors.get( 0 );
			assert e instanceof NameException || e instanceof ContentException;
			if ( e instanceof NameException )
				throw (NameException) e;
			if ( e instanceof ContentException )
				throw (ContentException) e;
		}
	}
	/**
	 * Adds the element name and names of nested element in it to name spaces.
	 * 
	 * @param content
	 *            the content to add
	 * @throws NameException
	 *             if any element has duplicate name with elements already on
	 *             the design tree.
	 */