override fun onRetryChange(timeMs: Long) {
          callbacks.add(timeMs)
        }
      }
    val buffer = Buffer().writeUtf8(source)
    val reader = ServerSentEventReader(buffer, callback)
    while (reader.processNextEvent()) {
    }
    assertThat(buffer.size, "Unconsumed buffer: ${buffer.readUtf8()}")
      .isEqualTo(0)
  }

 * attempts to the current point use this function.
 *
 * ```java
 * private int responseCount(Response response) {
 *   int result = 1;
 *   while ((response = response.priorResponse()) != null) {
 *     result++;
 *   }
 *   return result;
 * }
 * ```
 *
 * [1]: https://tools.ietf.org/html/rfc2817
 */
fun interface Authenticator {
  /**

        return EventListener.NONE;
      }
    }
  };

  ...
}
```

### Events with Failures

When an operation fails, a failure method is called. This is `connectFailed()` for failures while building a connection to the server, and `callFailed()` when the HTTP call fails permanently. When a failure happens it is possible that a `start` event won’t have a corresponding `end` event.

    makeSimpleCall()
  }

  /**
   * If the server returns a full response, it doesn't really matter if the HTTP/2 stream is reset.
   * Attempts to write the request body fails fast.
   */
  @Test
  fun serverTruncatesRequestHttp2OnDuplexRequest() {
    enableProtocol(Protocol.HTTP_2)

    server.enqueue(
      MockResponse(
        body = "abc",

      return hex.decodeHex().toResponseBody(mediaType)
    }

    fun exhaust(reader: Reader): String {
      val builder = StringBuilder()
      val buf = CharArray(10)
      var read: Int
      while (reader.read(buf).also { read = it } != -1) {
        builder.appendRange(buf, 0, read)
      }
      return builder.toString()
    }
  }

 *  Fix: Include the header `Accept: text/event-stream` for SSE calls. This header is not added if
    the request already contains an `Accept` header.

 *  Fix: Don't crash with a `NullPointerException` if a server sends a close while we're sending a
    ping. OkHttp had a race condition bug.


## Version 4.6.0

_2020-04-28_

 *  Fix: Follow HTTP 307 and 308 redirects on methods other than GET and POST. We're reluctant to

### Threads

#### Application's calling thread

The application-layer must block on writing I/O. We can't return from a write until we've pushed its bytes onto the socket. Otherwise, if the write fails we are unable to deliver its IOException to the application. We would have told the application layer that the write succeeded, but it didn't!

private fun Buffer.readQuotedString(): String? {
  require(readByte() == '\"'.code.toByte())
  val result = Buffer()
  while (true) {
    val i = indexOfElement(QUOTED_STRING_DELIMITERS)
    if (i == -1L) return null // Unterminated quoted string.

    if (this[i] == '"'.code.toByte()) {
      result.write(this, i)
      // Consume '"'.
      readByte()
      return result.readUtf8()
    }

      }
      println()
    }

    // Stream the response to the System.out as it is returned from the server.
    val out = System.out.sink()
    val source = response.body.source()
    while (!source.exhausted()) {
      out.write(source.buffer, source.buffer.size)
      out.flush()
    }

    response.body.close()
  } catch (e: IOException) {
    e.printStackTrace()
  } finally {
    close()
  }

 *     .build();
 * ```
 *
 * ## Force a Cache Response
 *
 * Sometimes you'll want to show resources if they are available immediately, but not otherwise.
 * This can be used so your application can show *something* while waiting for the latest data to be
 * downloaded. To restrict a request to locally-cached resources, add the `only-if-cached`
 * directive:
 *
 * ```java
 * Request request = new Request.Builder()