assertEquals("text/plain", child.getMimeType());
child.addField("Content-Type", " child/type");
assertEquals("child/type", child.getMimeType());
parent = new BodyDescriptor();
parent.addField("Content-Type", "multipart/digest; boundary=foo");
child = new BodyDescriptor(parent);
assertEquals("message/rfc822", child.getMimeType());
child.addField("Content-Type", " child/type");
assertEquals("child/type", child.getMimeType());