@Test(expected = SignatureException.class)
public void badSig() throws Exception {

    byte[] fakePatch = new byte[1024];
    Arrays.fill(fakePatch, (byte) 0x42);
    paths.put("/2.jar.bpatch", fakePatch);
    UFXProtocol.SignedUpdates.Builder builder = makeWrongIndex();
    builder.setSignatures(0, "bzzzz");
    paths.put("/index", builder.build().toByteArray());
    updater = new TestUpdater(indexURL, "UnitTest", dir, null);
    updater.call();
}