Iterables.addAll(queue, elements);
    return queue;
  }

  // SynchronousQueue

  /** Creates an empty {@code SynchronousQueue} with nonfair access policy. */
  @J2ktIncompatible
  @GwtIncompatible // SynchronousQueue
  public static <E> SynchronousQueue<E> newSynchronousQueue() {
    return new SynchronousQueue<>();
  }

  /**

    }

    /**
     * {@link SynchronousQueue}の新しいインスタンスを作成して返します。
     *
     * @param <E>
     *            {@link SynchronousQueue}の要素型
     * @return {@link SynchronousQueue}の新しいインスタンス
     * @see SynchronousQueue#SynchronousQueue()
     */
    public static <E> SynchronousQueue<E> newSynchronousQueue() {
        return new SynchronousQueue<>();
    }

    /**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.internal.concurrent

import java.util.concurrent.BlockingQueue
import java.util.concurrent.SynchronousQueue
import java.util.concurrent.ThreadFactory
import java.util.concurrent.ThreadPoolExecutor
import java.util.concurrent.TimeUnit
import java.util.concurrent.locks.Condition
import java.util.concurrent.locks.ReentrantLock

 * limitations under the License.
 */
package okhttp3

import java.util.ArrayDeque
import java.util.Collections
import java.util.Deque
import java.util.concurrent.ExecutorService
import java.util.concurrent.SynchronousQueue
import java.util.concurrent.ThreadPoolExecutor
import java.util.concurrent.TimeUnit
import java.util.concurrent.locks.ReentrantLock
import okhttp3.internal.assertNotHeld
import okhttp3.internal.connection.Locks.withLock

import java.util.Arrays
import java.util.concurrent.BlockingQueue
import java.util.concurrent.CountDownLatch
import java.util.concurrent.Executors
import java.util.concurrent.LinkedBlockingQueue
import java.util.concurrent.SynchronousQueue
import java.util.concurrent.TimeUnit
import java.util.concurrent.TimeoutException
import java.util.concurrent.atomic.AtomicReference
import javax.net.ssl.SSLException
import kotlin.test.assertFailsWith

import java.time.Duration
import java.util.Arrays
import java.util.concurrent.BlockingQueue
import java.util.concurrent.CountDownLatch
import java.util.concurrent.Executors
import java.util.concurrent.SynchronousQueue
import java.util.concurrent.TimeUnit
import java.util.concurrent.atomic.AtomicBoolean
import java.util.concurrent.atomic.AtomicInteger
import java.util.concurrent.atomic.AtomicReference
import javax.net.ssl.SSLException