val response2 = get(url)
    assertThat(response2.body.string()).isEqualTo("A")
    assertThat(response2.header("Warning")).isNull()
  }

  @Test
  fun defaultExpirationDateConditionallyCached() {
    //      last modified: 115 seconds ago
    //             served:  15 seconds ago
    //   default lifetime: (115 - 15) / 10 = 10 seconds