MockResponse(
        headers =
          headersOf(
            "B",
            "123",
            "B",
            "234",
          ),
      ),
    )
    executeSynchronously("/", "A", "345", "A", "456")
      .assertCode(200)
      .assertHeader("B", "123", "234")
    val recordedRequest = server.takeRequest()
    assertThat(recordedRequest.headers.values("A")).containsExactly("345", "456")
  }