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",

### [Fast Fallback](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-ok-http-client/-builder/fast-fallback/)

Since version 5.0, `OkHttpClient` supports fast fallback, which is our implementation of Happy Eyeballs [RFC 6555](https://datatracker.ietf.org/doc/html/rfc6555).

## Version 5.0.0-alpha.4

_2022-02-01_

**This release introduces fast fallback to better support mixed IPv4+IPv6 networks.** Fast fallback
is what we're calling our implementation of Happy Eyeballs, [RFC 8305][rfc_8305]. With this
feature OkHttp will attempt both IPv6 and IPv4 connections concurrently, keeping whichever connects
first. Fast fallback gives IPv6 connections a 250 ms head start so IPv6 is preferred on networks

    coders call this and we don't want their users to suffer.


## Version 4.0.0

_2019-06-26_

**This release upgrades OkHttp to Kotlin.** We tried our best to make fast and safe to upgrade
from OkHttp 3.x. We wrote an [upgrade guide][upgrading_to_okhttp_4] to help with the migration and a
[blog post][okhttp4_blog_post] to explain it.

 *  Fix: Target Java 8 bytecode for Java and Kotlin.

# FORMAT NOT DOCUMENTED YET (parser is urltestparser.js)

# Based on http://trac.webkit.org/browser/trunk/LayoutTests/fast/url/script-tests/segments.js
http://example\t.\norg http://example.org/foo/bar s:http h:example.org p:/
http://user:pass@foo:21/bar;par?b#c  s:http u:user pass:pass h:foo port:21 p:/bar;par q:?b f:#c
http:foo.com  s:http h:example.org p:/foo/foo.com
\t\s\s\s:foo.com\s\s\s\n  s:http h:example.org p:/foo/:foo.com

---
name: Bug report
about: A reproducible problem
title: ''
labels: bug
assignees: ''

---

Good bug reports include a failing test! Writing a test helps you to isolate and describe the problem, and it helps us to fix it fast. Bug reports without a failing test or reproduction steps are likely to be closed.

Here’s an example test to get you started.

import java.util.Date
import java.util.Locale
import okhttp3.internal.UTC

/** The last four-digit year: "Fri, 31 Dec 9999 23:59:59 GMT". */
internal const val MAX_DATE = 253402300799999L

/**
 * Most websites serve cookies in the blessed format. Eagerly create the parser to ensure such
 * cookies are on the fast path.
 */
private val STANDARD_DATE_FORMAT =
  object : ThreadLocal<DateFormat>() {

 */
package okhttp3

import okio.IOException

/**
 * Listener for connection events. Extend this class to monitor the new connections and closes.
 *
 * All event methods must execute fast, without external locking, cannot throw exceptions,
 * attempt to mutate the event parameters, or be reentrant back into the client.
 * Any IO - writing to files or network should be done asynchronously.
 */
@ExperimentalOkHttpApi

 * MockWebServer. In cases where logic is particularly tricky, we use unit tests. This class makes
 * it easy to get sample values to use in such tests.
 *
 * This class is pretty fast and loose with default values: it attempts to provide values that are
 * well-formed, but doesn't guarantee values are internally consistent. Callers must take care to

        plusIsSpace = plusIsSpace,
        unicodeAllowed = unicodeAllowed,
        charset = charset,
      )
      return out.readUtf8()
    }
    i += Character.charCount(codePoint)
  }

  // Fast path: no characters in [pos..limit) required encoding.
  return substring(pos, limit)
}

internal fun Buffer.writePercentDecoded(
  encoded: String,
  pos: Int,
  limit: Int,
  plusIsSpace: Boolean,