@Test
public void shouldCacheKeysOnFetches() throws Exception {

  KeysDownloader instance = newInstanceForTests();
  httpResponseBuilder = new HttpResponseBuilder().setContent("keys1");
  // Fetched and cached keys
  assertEquals("keys1", instance.download());
  // Keys changed
  httpResponseBuilder = new HttpResponseBuilder().setContent("keys2");
  // Old keys are returned
  assertEquals("keys1", instance.download());
}