- Favour a working external library if appropriate.  There are many examples of OkHttp libraries that can sit on top or hook in via existing APIs.
- Get working code on a personal branch with tests before you submit a PR.
- OkHttp is a small and light dependency.  Don't introduce new dependencies or major new functionality.

import org.opentest4j.TestAbortedException

/**
 * This test binds two different web servers (IPv4 and IPv6) to the same port, but on different
 * local IP addresses. Requests made to `127.0.0.1` will reach the IPv4 server, and requests made to
 * `::1` will reach the IPv6 server.
 *
 * By orchestrating two different servers with the same port but different IP addresses, we can
 * test what OkHttp does when both are reachable, or if only one is reachable.
 *

    why we're doing this and how to upgrade.

    The OkHttp 3.12.x branch will be our long-term branch for Android 2.3+ (API level 9+) and Java
    7+. These platforms lack support for TLS 1.2 and should not be used. But because upgrading is
    difficult we will backport critical fixes to the 3.12.x branch through December 31, 2021. (This
    commitment was originally through December 31, 2020; we have since extended it.)

 * q: cute #puppies
 * f: images
 * ```
 *
 * In addition to composing URLs from their component parts and decomposing URLs into their
 * component parts, this class implements relative URL resolution: what address you'd reach by
 * clicking a relative link on a specified page. For example:
 *
 * ```java
 * HttpUrl base = HttpUrl.parse("https://www.youtube.com/user/WatchTheDaily/videos");
 * HttpUrl link = base.resolve("../../watch?v=cbP2N1BQdYc");

import okio.source

/**
 * A single attempt to connect to a remote server, including these steps:
 *
 *  * [TCP handshake][connectSocket]
 *  * Optional [CONNECT tunnels][connectTunnel]. When using an HTTP proxy to reach an HTTPS server
 *    we must send a `CONNECT` request, and handle authorization challenges from the proxy.
 *  * Optional [TLS handshake][connectTls].
 *

 * limitations under the License.
 */
package okhttp3

import java.net.InetSocketAddress
import java.net.Proxy
import okhttp3.internal.toCanonicalHost

/**
 * The concrete route used by a connection to reach an abstract origin server. When creating a
 * connection the client has many options:
 *
 *  * **HTTP proxy:** a proxy server may be explicitly configured for the client. Otherwise, the

the first security provider:

```java
Security.insertProviderAt(Conscrypt.newProvider(), 1);
```

The OkHttp `3.12.x` branch supports Android 2.3+ (API level 9+) and Java 7+. These platforms lack
support for TLS 1.2 and should not be used.


Releases
--------

Our [change log][changelog] has release history.

_2015-03-16_

 *  **HTTP/2 support.** We've done interop testing and haven't seen any
    problems. HTTP/2 support has been a big effort and we're particularly
    thankful to Adrian Cole who has helped us to reach this milestone.

 *  **RC4 cipher suites are no longer supported by default.** To connect to
    old, obsolete servers relying on these cipher suites, you must create a
    custom `ConnectionSpec`.

     * this client silently recovers from the following problems:
     *
     * * **Unreachable IP addresses.** If the URL's host has multiple IP addresses,
     *   failure to reach any individual IP address doesn't fail the overall request. This can
     *   increase availability of multi-homed services.
     *
     * * **Stale pooled connections.** The [ConnectionPool] reuses sockets

    } else {
      frameCallback.onReadMessage(messageFrameBuffer.readByteString())
    }
  }

  /** Read headers and process any control frames until we reach a non-control frame. */
  @Throws(IOException::class)
  private fun readUntilNonControlFrame() {
    while (!closed) {
      readHeader()
      if (!isControlFrame) {
        break
      }