serviceTracker2.open();
Assert.assertTrue(serviceTracker2.size() > 0);
// gets service by class and filter
Echo echo = (Echo) serviceTracker2.getService();
// asserts service method call
Assert.assertEquals("test", echo.echo("test"));
// stops bundle
bundle.stop();
// asserts that test bundle is resolved
Assert.assertEquals(Bundle.RESOLVED, bundle.getState());
// asserts that test service is unregistered