assertThat(response2.header("X-Response-ID")).isEqualTo("1")
    } else {
      assertThat(response2.header("X-Response-ID")).isEqualTo("2")
    }
  }

  private fun requestBodyOrNull(requestMethod: String): RequestBody? {
    return if (requestMethod == "POST" || requestMethod == "PUT") "foo".toRequestBody("text/plain".toMediaType()) else null
  }

  @Test
  fun postInvalidatesCache() {