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
assertTrue( image.getModule( ) instanceof Library );
		LibraryHandle lib2 = designHandle.getLibrary( "Lib2" ); 
		assertNull( lib2 );
		
		assertEquals( 2, designHandle.getAllImages( ).size( ) );
		assertEquals( 4, lib1.getAllImages( ).size( ) );
	}
	/**
	 * Tests isReadOnly in PropertyHandle.
	 * 
	 * @throws Exception
	 */
	public void testReadOnly( ) throws Exception
	{
		openDesign( "DesignWithOneLibrary.xml" ); 
		assertNotNull( designHandle );
		libraryHandle = designHandle.getLibrary( "Lib1" ); 
		assertNotNull( libraryHandle );
		PropertyHandle propertyHandle = libraryHandle
				.getPropertyHandle( Module.CREATED_BY_PROP );
		assertTrue( propertyHandle.isReadOnly( ) );
		propertyHandle = designHandle
				.getPropertyHandle( Module.CREATED_BY_PROP );
		assertFalse( propertyHandle.isReadOnly( ) );
	}
	/**
	 * Tests property value of elements that is extended in multi-level.
	 * 
	 * cases:
	 * <ul>