.header("Connection", "upgrade")
        .build()
    assertFailsWith<ProtocolException> {
      client.newCall(requestWithUpgrade).execute()
    }
  }

  @Test
  fun upgradesOnReusedConnection() {
    server.enqueue(MockResponse(body = "normal request"))
    client.newCall(Request(server.url("/"))).execute().use { response ->
      assertThat(response.body.string()).isEqualTo("normal request")
    }