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
PropertyHandle propHandle = designHandle
				.getPropertyHandle( ReportDesignHandle.LIBRARIES_PROP );
		List includeLibraries = propHandle.getListValue( );
		assertEquals( 1, includeLibraries.size( ) );
		IncludedLibrary includeLibrary = (IncludedLibrary) includeLibraries
				.get( 0 );
		assertEquals( "Library_1.xml", includeLibrary.getFileName( ) ); 
		
		assertEquals( 1, designHandle.getAllLibraries( ).size( ) );
		LibraryHandle libHandle = (LibraryHandle) designHandle
				.getAllLibraries( ).get( 0 );
		assertTrue( libHandle.getFileName( ).endsWith( "Library_1.xml" ) ); 
		assertEquals( "W.C. Fields", libHandle.getAuthor( ) ); 
		DesignElementHandle pageHandle = libHandle.getMasterPages( ).get( 0 );
		assertEquals( "My Page", pageHandle.getName( ) ); 
		
		designHandle.getCommandStack( ).undo( );
		
		includeLibraries = propHandle.getListValue( );
		assertNull( includeLibraries );
		
		assertEquals( 0, designHandle.getAllLibraries( ).size( ) );
		
		designHandle.getCommandStack( ).redo( );
		
		propHandle = designHandle
				.getPropertyHandle( ReportDesignHandle.LIBRARIES_PROP );
		includeLibraries = propHandle.getListValue( );
		assertEquals( 1, includeLibraries.size( ) );