@Override
    public PackageRevision responseMessageForLatestRevisionSince(String responseBody) {
        return toPackageRevision(responseBody);
    }
@Test
    public void shouldBuildNullPackageRevisionFromLatestRevisionSinceWhenEmptyResponse() throws Exception {
        assertThat(messageHandler.responseMessageForLatestRevisionSince(""), nullValue());
        assertThat(messageHandler.responseMessageForLatestRevisionSince(null), nullValue());
        assertThat(messageHandler.responseMessageForLatestRevisionSince("{}"), nullValue());
    }