val relay = edit(file, upstream, metadata, 5)
    val source1 = relay.newSource()!!.buffer()
    val source2 = relay.newSource()!!.buffer()
    assertThat(source1.readUtf8(5)).isEqualTo("abcde")
    assertThat(source2.readUtf8(5)).isEqualTo("abcde")
    assertThat(source2.readUtf8(5)).isEqualTo("fghij")
    assertThat(source1.readUtf8(5)).isEqualTo("fghij")
    assertThat(source1.exhausted()).isTrue()

    protocol: Protocol,
    mockWebServer: MockWebServer,
  ) {
    setUp(protocol, mockWebServer)
    server.enqueue(MockResponse(body = "ABCDE"))
    val call = client.newCall(Request(server.url("/foo")))
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("ABCDE")
    assertThat(response.code).isEqualTo(200)
    assertThat(response.message).isEqualTo("")
    assertThat(response.protocol).isEqualTo(protocol)

    transferKind.setBody(mockResponse, "ABCDE\nFGHIJKLMNOPQRSTUVWXYZ", 16)
    server.enqueue(truncateViolently(mockResponse, 16).build())
    server.enqueue(
      MockResponse.Builder()
        .body("Request #2")
        .build(),
    )
    val bodySource = get(server.url("/")).body.source()
    assertThat(bodySource.readUtf8Line()).isEqualTo("ABCDE")
    bodySource.use {
      assertFailsWith<IOException> {

    peer.acceptFrame() // PING
    peer.sendFrame().ping(true, Http2Connection.AWAIT_PING, 0)
    peer.acceptFrame() // HEADERS STREAM 3
    peer.sendFrame().windowUpdate(3, 5)
    peer.acceptFrame() // DATA STREAM 3 "abcde"
    peer.sendFrame().windowUpdate(3, 5)
    peer.acceptFrame() // DATA STREAM 3 "fghi"
    peer.play()

    // Play it back.
    val connection = connect(peer)