internal const val B0_FLAG_RSV3 = 16

  /** Byte 0 mask for the frame opcode. */
  internal const val B0_MASK_OPCODE = 15

  /** Flag in the opcode which indicates a control frame. */
  internal const val OPCODE_FLAG_CONTROL = 8

  /**
   * Byte 1 flag for whether the payload data is masked.
   *
   * If this flag is set, the next four

    TYPE_DISALLOWED -> TYPE_DISALLOWED

    else -> error("unexpected type: $type")
  }
}

internal infix fun Byte.and(mask: Int): Int = toInt() and mask

internal infix fun Short.and(mask: Int): Int = toInt() and mask

   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

  companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {

  server.enqueue(new MockResponse().setBody("sup, bra?"));
  server.enqueue(new MockResponse().setBody("yo dog"));

  // Start the server.
  server.start();

  // Ask the server for its URL. You'll need this to make HTTP requests.
  HttpUrl baseUrl = server.url("/v1/chat/");

  // Exercise your application code, which should make those HTTP requests.

import java.io.IOException
import java.util.Random
import okhttp3.internal.ws.WebSocketProtocol.B0_FLAG_FIN
import okhttp3.internal.ws.WebSocketProtocol.B0_FLAG_RSV1
import okhttp3.internal.ws.WebSocketProtocol.B1_FLAG_MASK
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_CLOSE
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_PING
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_PONG

 *
 * Recurrence
 * ----------
 *
 * Tasks control their recurrence schedule. The [runOnce] function returns -1L to signify that the
 * task should not be executed again. Otherwise it returns a delay until the next execution.
 *
 * A task has at most one next execution. If the same task instance is scheduled multiple times, the
 * earliest one wins. This applies to both executions scheduled with [TaskRunner.Queue.schedule] and

   * is running when that time is reached, that task is allowed to complete before this task is
   * started. Similarly the task will be delayed if the host lacks compute resources.
   *
   * @throws RejectedExecutionException if the queue is shut down and the task is not cancelable.
   */
  fun schedule(
    task: Task,
    delayNanos: Long = 0L,
  ) {

import java.io.IOException
import java.util.concurrent.CopyOnWriteArrayList
import java.util.concurrent.LinkedBlockingDeque
import java.util.concurrent.TimeUnit
import okhttp3.internal.concurrent.Task
import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.RoutePlanner.ConnectResult
import okhttp3.internal.connection.RoutePlanner.Plan
import okhttp3.internal.okHttpName

/**

Releasing
=========

### Prerequisite: Sonatype (Maven Central) Account

Create an account on the [Sonatype issues site][sonatype_issues]. Ask an existing publisher to open
an issue requesting publishing permissions for `com.squareup` projects.


Cutting a Release
-----------------

1. Update `CHANGELOG.md`.

2. Set versions:

    ```
    export RELEASE_VERSION=X.Y.Z
    export NEXT_VERSION=X.Y.Z-SNAPSHOT
    ```

#### Blocking APIs

Blocking APIs are convenient because you get top-to-bottom procedural code without indirection. Network calls work like regular method calls: ask for data and it is returned. If the request fails, you get a stacktrace right where the call was made.