return ImmutableMap.of();
  }

  @Override
  protected Map<String, Integer> makePopulatedMap() {
    return ImmutableMap.of("one", 1, "two", 2, "three", 3);
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "minus one";
  }

  @Override
  protected Integer getValueNotInPopulatedMap() {
    return -1;
  }

  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nullDuplicatesNotRejected() {
    expectFirstRemoved(getEntriesMultipleNullKeys());
  }

  @MapFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testCreateWithDuplicates_nonNullDuplicatesNotRejected() {

 */

package com.google.common.collect.testing.google;

import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

   * to thread contention. But overestimates and underestimates within an order of magnitude do not
   * usually have much noticeable impact. A value of one permits only one thread to modify the cache
   * at a time, but since read operations and cache loading computations can proceed concurrently,
   * this still yields higher concurrency than full synchronization.
   *

    }

    /**
     * Retrieves the current thread's {@link UrlQueue} instance.
     *
     * @return the {@link UrlQueue} instance associated with the current thread, or {@code null} if none is set.
     */
    public static UrlQueue<?> getUrlQueue() {
        return URL_QUEUE_THREAD_LOCAL.get();
    }

    /**
     * Sets the URL queue for the current thread. If the provided URL queue is null,

      0xFFFF - 0x0800 + 1 - THREE_BYTE_SURROGATES;

  // 2,650,112
  private static final long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
      // All one byte characters
      (long) Math.pow(EXPECTED_ONE_BYTE_ROUNDTRIPPABLE_COUNT, 3)
          +
          // One two byte character and a one byte character
          2 * TWO_BYTE_ROUNDTRIPPABLE_CHARACTERS * ONE_BYTE_ROUNDTRIPPABLE_CHARACTERS
          +
          // Three byte characters

     *
     * @param args
     *            the constructor arguments
     * @return a {@link ConstructorDesc} that matches the arguments, or {@literal null} if none exists
     */
    protected ConstructorDesc findSuitableConstructorDesc(final Object... args) {
        for (final ConstructorDesc constructorDesc : constructorDescs) {

So we have a dedicated thread for every socket that just reads frames and dispatches them.

The reader thread must never run application-layer code. Otherwise one slow stream can hold up the entire connection.

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

import java.io.IOException

/** Attempt routes one at a time until one connects. */
internal class SequentialExchangeFinder(
  override val routePlanner: RoutePlanner,
) : ExchangeFinder {
  override fun find(): RealConnection {
    var firstException: IOException? = null

    super(false, true, true, true, true);
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    NavigableMap<String, Integer> map = new SafeTreeMap<>();
    map.put("one", 1);
    map.put("two", 2);
    map.put("three", 3);
    return SerializableTester.reserialize(map);
  }

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() throws UnsupportedOperationException {