return CollectCollectors.toImmutableSet();
  }

  /**
   * Returns the empty immutable set. Preferred over {@link Collections#emptySet} for code
   * consistency, and because the return type conveys the immutability guarantee.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings({"unchecked"}) // fully variant implementation (never actually produces any Es)

        // Then
        assertTrue(request instanceof ServerMessageBlock2Request);
        assertTrue(request instanceof ServerMessageBlock2);
    }

    @Test
    @DisplayName("Should maintain immutability of structure size")
    void testStructureSizeImmutability() throws Exception {
        // Given
        byte[] buffer = new byte[2048];

        // When - encode at multiple positions

## Version 2.0.0-RC1

_2014-05-23_

OkHttp 2 is designed around a new API that is true to HTTP, with classes for
requests, responses, headers, and calls. It uses modern Java patterns like
immutability and chained builders. The API now offers asynchronous callbacks
in addition to synchronous blocking calls.

#### API Changes

 *  **New Request and Response types,** each with their own builder. There's also

  /**
   * Verifies that the {@code Set} returned by {@code nodes} has the expected mutability property
   * (see the {@code Graph} documentation for more information).
   */
  @Test
  public abstract void nodes_checkReturnedSetMutability();

  /**
   * Verifies that the {@code Set} returned by {@code adjacentNodes} has the expected mutability
   * property (see the {@code Graph} documentation for more information).
   */

  /**
   * Verifies that the {@code Set} returned by {@code nodes} has the expected mutability property
   * (see the {@code Graph} documentation for more information).
   */
  @Test
  public abstract void nodes_checkReturnedSetMutability();

  /**
   * Verifies that the {@code Set} returned by {@code adjacentNodes} has the expected mutability
   * property (see the {@code Graph} documentation for more information).
   */

    Iterables.addAll(set, iterable);
    return set;
  }

  // HashSet

  /**
   * Creates a <i>mutable</i>, initially empty {@code HashSet} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableSet#of()} instead. If {@code
   * E} is an {@link Enum} type, use {@link EnumSet#noneOf} instead. Otherwise, strongly consider

 * @since 2.0
 */
@GwtCompatible
public final class Lists {
  private Lists() {}

  // ArrayList

  /**
   * Creates a <i>mutable</i>, empty {@code ArrayList} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableList#of()} instead.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,

    return CollectCollectors.toImmutableEnumMap(keyFunction, valueFunction, mergeFunction);
  }

  /**
   * Creates a <i>mutable</i>, empty {@code HashMap} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableMap#of()} instead.
   *
   * <p><b>Note:</b> if {@code K} is an {@code enum} type, use {@link #newEnumMap} instead.
   *

    return CollectCollectors.toImmutableEnumMap(keyFunction, valueFunction, mergeFunction);
  }

  /**
   * Creates a <i>mutable</i>, empty {@code HashMap} instance.
   *
   * <p><b>Note:</b> if mutability is not required, use {@link ImmutableMap#of()} instead.
   *
   * <p><b>Note:</b> if {@code K} is an {@code enum} type, use {@link #newEnumMap} instead.
   *