Bug 164070 Support widows/orphans properties on text item
Support widows/orphans properties on block text item(label, text, data etc), About the definition of widows/orphans, please refer to CSS spec.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/api/DesignElementHandleTest.java
* <ul>
	 * <li>
	 * {@link org.eclipse.birt.report.model.api.DesignElementHandle#getExtends()}
	 * <li>
	 * {@link org.eclipse.birt.report.model.api.DesignElementHandle#setExtends(DesignElementHandle)}
	 * <li>
	 * {@link org.eclipse.birt.report.model.api.DesignElementHandle#setExtendsElement}
	 * <li>
	 * {@link org.eclipse.birt.report.model.api.DesignElementHandle#setExtendsName(String)}
	 * <li>
	 * {@link org.eclipse.birt.report.model.api.DesignElementHandle#derivedIterator()}
	 * </ul>
	 * 
	 * @throws Exception
	 *             if any exception
	 */
	public void testExtends( ) throws Exception
	{
		DesignElementHandle label4Handle = designHandle
				.findElement( "bodyLabel4" ); 
		DesignElementHandle parentHandle = label4Handle.getExtends( );
		assertEquals( "base", parentHandle.getName( ) ); 
		label4Handle = designHandle.findElement( "label3" ); 
		parentHandle = label4Handle.getExtends( );
		assertEquals( "child1", parentHandle.getName( ) ); 
		parentHandle = parentHandle.getExtends( );
		assertEquals( "base", parentHandle.getName( ) ); 
		label4Handle = designHandle.findElement( "label2" ); 
		label4Handle.setExtendsName( "base" ); 
		assertEquals( "base", label4Handle.getExtends( ).getName( ) );