Bug 183918 get relative file path of linkage library
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/library/DesignLoadLibraryTest.java
{
			designHandle.dropLibrary( lib2Handle );
			fail( );
		}
		catch ( SemanticException e )
		{
			assertEquals(
					LibraryException.DESIGN_EXCEPTION_LIBRARY_HAS_DESCENDENTS,
					e.getErrorCode( ) );
		}
		designHandle.dropLibraryAndBreakExtends( lib2Handle );
		assertNull( mylabelHandle.getElement( ).getExtendsElement( ) );
		
		Label myLabel = (Label) mylabelHandle.getElement( );
		assertEquals(
				"25pt", myLabel.getLocalProperty( designHandle.getModule( ), Label.HEIGHT_PROP ).toString( ) ); 
		assertEquals(
				"red", myLabel.getLocalProperty( designHandle.getModule( ), StyleHandle.COLOR_PROP ).toString( ) ); 
		assertEquals(
				"First Page", myLabel.getLocalProperty( designHandle.getModule( ), Label.TEXT_PROP ) ); 
		
		assertEquals( 0, designHandle.getListProperty( Module.LIBRARIES_PROP )
				.size( ) );
		save( );
		compareFile( "TestDropLibrary_golden2.xml" ); 
		design.getActivityStack( ).undo( );
		Label baseLabel = (Label) mylabelHandle.getElement( )
				.getExtendsElement( );
		assertNotNull( baseLabel );