![Events Diagram](../assets/images/******@****.***)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java
class PrintingEventListener extends EventListener {
  private long callStartNanos;

import kotlinx.serialization.Serializable
import kotlinx.serialization.decodeFromString
import kotlinx.serialization.json.Json

/**
 * A test from the [Web Platform To ASCII](https://github.com/web-platform-tests/wpt/blob/master/url/resources/toascii.json).
 *
 * Each test is a line of the file `toascii.json`.
 */
@Serializable
class WebPlatformToAsciiData {
  var input: String? = null
  var output: String? = null

 */

package okhttp3.internal.http

// HTTP Status Codes not offered by HttpUrlConnection.
//
// https://datatracker.ietf.org/doc/html/rfc7231#page-47
//
// From https://github.com/apache/httpcomponents-core/blob/master/httpcore5/src/main/java/org/apache/hc/core5/http/HttpStatus.java

/** `100 Continue` (HTTP/1.1 - RFC 7231)  */
const val HTTP_CONTINUE = 100

/** `102 Processing` (WebDAV - RFC 2518)  */

[2020-01-01 00:00:00] Q10000 run again after 300 s : OkHttp ConnectionPool
[2020-01-01 00:00:00] Q10000 finished run in 739 µs: OkHttp ConnectionPool
```

appropriate, up to and including a permanent ban from all of Square spaces without warning.


[codeofconduct_at]: mailto:******@****.***
[twitter_coc]: https://github.com/twitter/code-of-conduct/blob/master/code-of-conduct.md
[ubuntu_coc]: https://ubuntu.com/community/code-of-conduct
[gdc_coc]: https://www.gdconf.com/code-of-conduct

 */
package okhttp3

import okhttp3.internal.format
import okio.Buffer
import okio.BufferedSource

/**
 * A test from the [Web Platform URL test suite](https://github.com/web-platform-tests/wpt/blob/master/url/resources/urltestdata.json).
 *
 * Each test is a line of the file `urltestdata.txt`. The format is informally specified by its
 * JavaScript parser `urltestparser.js` with which this class attempts to be compatible.
 *

   * quickly, possibly by handing off the provided request body to another thread to perform
   * writing.
   *
   * [grpc]: https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
   */
  open fun isDuplex(): Boolean = commonIsDuplex()

  /**
   * Returns true if this body expects at most one call to [writeTo] and can be transmitted

#
#       There are tweaks for specific operating systems such as AIX, CygWin,
#       Darwin, MinGW, and NonStop.
#
#   (3) This script is generated from the Groovy template
#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
#       within the Gradle project.
#
#       You can find Gradle at https://github.com/gradle/gradle/.
#

    in 191..242 -> "8.1.13.v20181017"
    else -> null
  }
}

/**
 * Returns the alpn-boot version specific to this OpenJDK 8 JVM, or null if this is not a Java 8 VM.
 * https://github.com/xjdr/xio/blob/master/alpn-boot.gradle
 */
fun alpnBootVersion(): String? {
  val version = System.getProperty("alpn.boot.version")

  if (version != null) {
    return version
  }

 [releasing]: https://square.github.io/okhttp/releasing/
 [security]: https://square.github.io/okhttp/security/
 [works_with_okhttp]: https://square.github.io/okhttp/works_with_okhttp/