import junit.framework.TestCase;
public class EntityTest extends TestCase {
public void testSetBody() throws Exception {
Entity entity = new BodyPart();
assertNull(entity.getBody());
Body body = new BodyFactory().textBody("test");
assertNull(body.getParent());
entity.setBody(body);
assertSame(body, entity.getBody());
assertSame(entity, body.getParent());
}