require(Protocol.H2_PRIOR_KNOWLEDGE in protocolsCopy || HTTP_1_1 in protocolsCopy) {
          "protocols must contain h2_prior_knowledge or http/1.1: $protocolsCopy"
        }
        require(Protocol.H2_PRIOR_KNOWLEDGE !in protocolsCopy || protocolsCopy.size <= 1) {
          "protocols containing h2_prior_knowledge cannot use other protocols: $protocolsCopy"
        }

          .hostnameVerifier(RecordingHostnameVerifier())
          .build()
      scheme = "https"
    } else {
      server.protocols = listOf(Protocol.H2_PRIOR_KNOWLEDGE)
      client =
        clientTestRule.newClientBuilder()
          .protocols(listOf(Protocol.H2_PRIOR_KNOWLEDGE))
          .build()
      scheme = "http"
    }
  }

  @AfterEach fun tearDown() {

    code][https_server_sample].

 *  **OkHttp now supports prior knowledge cleartext HTTP/2.** Enable this by setting
    `Protocol.H2_PRIOR_KNOWLEDGE` as the lone protocol on an `OkHttpClient.Builder`. This mode
    only supports `http:` URLs and is best suited in closed environments where HTTPS is
    inappropriate.

public final class okhttp3/OkHttpClient$Companion {
}

public final class okhttp3/Protocol : java/lang/Enum {
	public static final field Companion Lokhttp3/Protocol$Companion;
	public static final field H2_PRIOR_KNOWLEDGE Lokhttp3/Protocol;
	public static final field HTTP_1_0 Lokhttp3/Protocol;
	public static final field HTTP_1_1 Lokhttp3/Protocol;
	public static final field HTTP_2 Lokhttp3/Protocol;