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
* 
	 * @throws Exception
	 *             if any exception
	 */
	public void testLibraryElementReadOnly( ) throws Exception
	{
		openDesign( "DesignWithThreeLibrary.xml" ); 
		final LibraryHandle library1 = (LibraryHandle) designHandle
				.getAllLibraries( ).get( 0 );
		assertEquals( "Lib1", library1.getNamespace( ) ); 
		
		assertFalse( designHandle.isReadOnly( ) );
		assertTrue( library1.isReadOnly( ) );
		
		
		StyleHandle style = library1.findStyle( "style1" ); 
		try
		{
			style
					.setFontVariant( DesignChoiceConstants.FONT_VARIANT_SMALL_CAPS );
			fail( );
		}
		catch ( Exception e )
		{
			assertTrue( e instanceof IllegalOperationException );
		}
	}
	/**
	 * Tests one design file including the library, which also includes another
	 * two libraries.