@Test
public void test_get_installed_version() throws IOException {

    ExtensionService extensionService = new ExtensionService(deliverableDir.getRoot().toPath());
    DeliverablePackage deliverablePackageA = new DeliverablePackage(extensionService.newDeliverable(deliverableDir.newFile( "my-extension-1.0.0.jar").toURI().toURL()),deliverableDir.getRoot().toPath(),extensionService.deliverableRegistry);
    assertThat(deliverablePackageA.getInstalledVersion()).isEqualTo("1.0.0");
    deliverableDir.getRoot().toPath().resolve("my-extension-1.0.0.jar").toFile().delete();
    assertThat(deliverablePackageA.getInstalledVersion()).isNull();
}