waitForDataFrames(Http2Connection.OKHTTP_CLIENT_WINDOW_SIZE)

    // Cancel the call and discard what we've buffered for the response body. This should free up
    // the connection flow-control window so new requests can proceed.
    call1.cancel()
    assertThat(
      response1.body.source().discard(1, TimeUnit.SECONDS),
      "Call should not have completed successfully.",
    ).isFalse()