chat.loadMore();
  assertEquals("hello, world!", chat.messages());

  chat.loadMore();
  chat.loadMore();
  assertEquals(""
      + "hello, world!\n"
      + "sup, bra?\n"
      + "yo dog", chat.messages());

  // Optional: confirm that your app made the HTTP requests you were expecting.
  RecordedRequest request1 = server.takeRequest();
  assertEquals("/v1/chat/messages/", request1.getPath());

This [sample factory](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEvents.java) creates a unique ID for each call and uses that ID to differentiate calls in log messages.

```java
class PrintingEventListener extends EventListener {
  public static final Factory FACTORY = new Factory() {
    final AtomicLong nextCallId = new AtomicLong(1L);

  }

  fun assertFailure(
    cls: Class<out IOException?>?,
    vararg messages: String,
  ) {
    val event = nextEvent() as Failure
    assertThat(event.response).isNull()
    assertThat(event.t.javaClass).isEqualTo(cls)
    if (messages.isNotEmpty()) {
      assertThat(messages).contains(event.t.message)
    }
  }

  fun assertFailure() {
    nextEvent() as Failure
  }

   * messages.
   */
  open fun onOpen(
    webSocket: WebSocket,
    response: Response,
  ) {
  }

  /** Invoked when a text (type `0x1`) message has been received. */
  open fun onMessage(
    webSocket: WebSocket,
    text: String,
  ) {
  }

  /** Invoked when a binary (type `0x2`) message has been received. */
  open fun onMessage(

    }

  fun assertFailure(vararg messages: String) =
    apply {
      assertThat(failure, "No failure found").isNotNull()
      assertThat(messages).contains(failure!!.message)
    }

  fun assertFailureMatches(vararg patterns: String) =
    apply {
      val message = failure!!.message!!
      assertThat(
        patterns.firstOrNull { pattern ->
          message.matches(pattern.toRegex())
        },

#### Http2Writer

Socket writes are guarded by the Http2Writer. Only one stream can write at a time so that messages are not interleaved. Writes are either made by application-layer threads or the do-stuff-later pool.

### Holding multiple locks

  @Override public synchronized void onOpen(WebSocket webSocket, Response response) {
    System.out.println("onOpen: " + response);
  }

  // TOOD(jwilson): decode incoming messages and dispatch them somewhere.
  @Override public void onMessage(WebSocket webSocket, String text) {
    System.out.println("onMessage: " + text);
  }

    }.also { expected ->
      assertThat(expected.message).isEqualTo("Code must be in range [1000,5000): 98724976")
    }
  }

  @Test fun closeReservedThrows() {
    assertFailsWith<IllegalArgumentException> {
      clientWriter.writeClose(1005, "Hello".encodeUtf8())
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Code 1005 is reserved and may not be used.")
    }
  }

     * deduped.
     *
     * TODO: See if duped headers should be preserved on decode and verify.
     */
    private fun assertSetEquals(
      message: String,
      expected: List<Header>,
      observed: List<Header>,
    ) {
      assertThat(LinkedHashSet(observed), message)
        .isEqualTo(LinkedHashSet(expected))
    }
  }

 */
package okhttp3.sse

import okhttp3.Call
import okhttp3.OkHttpClient
import okhttp3.Response
import okhttp3.sse.internal.RealEventSource

object EventSources {
  @Deprecated(
    message = "required for binary-compatibility!",
    level = DeprecationLevel.HIDDEN,
  )
  @JvmStatic
  fun createFactory(client: OkHttpClient) = createFactory(client as Call.Factory)

  @JvmStatic