@Test public void parseCacheHeaders_noHeaders() {

    NetworkResponse response = new NetworkResponse(0, new byte[0], Headers.of(headers), 0);
    Cache.Entry entry = HttpHeaderParser.parseCacheHeaders(response);
    assertNotNull(entry);
    assertNull(entry.etag);
    assertEquals(0, entry.serverDate);
    assertEquals(0, entry.lastModified);
    assertEquals(0, entry.ttl);
    assertEquals(0, entry.softTtl);
}