@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
  static <E extends Enum<E>> ImmutableSet<E> asImmutable(EnumSet<E> set) {
    switch (set.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(set));
      default:
        return new ImmutableEnumSet<>(set);
    }
  }

  /*

@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
  static <E extends Enum<E>> ImmutableSet<E> asImmutable(EnumSet<E> set) {
    switch (set.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(set));
      default:
        return new ImmutableEnumSet<>(set);
    }
  }

  /*

 */

package com.google.common.collect;

import java.util.Set;

/**
 * GWT emulation of {@link ImmutableEnumSet}. The type parameter is not bounded by {@code Enum<E>}
 * to avoid code-size bloat.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E> extends ForwardingImmutableSet<E> {
  static <E> ImmutableSet<E> asImmutable(Set<E> delegate) {
    switch (delegate.size()) {

    Set<SomeEnum> units = Sets.immutableEnumSet(SomeEnum.D, SomeEnum.B);

    assertThat(units).containsExactly(SomeEnum.B, SomeEnum.D).inOrder();

    Set<SomeEnum> copy = SerializableTester.reserializeAndAssert(units);
    assertTrue(copy instanceof ImmutableEnumSet);
  }

  public void testImmutableEnumSet_fromIterable() {
    ImmutableSet<SomeEnum> none = Sets.immutableEnumSet(MinimalIterable.<SomeEnum>of());

    assertTrue(copy instanceof ImmutableEnumSet);
  }

  public void testImmutableEnumSet_fromIterable() {
    ImmutableSet<SomeEnum> none = Sets.immutableEnumSet(MinimalIterable.<SomeEnum>of());
    assertThat(none).isEmpty();

    ImmutableSet<SomeEnum> one = Sets.immutableEnumSet(MinimalIterable.of(SomeEnum.B));
    assertThat(one).contains(SomeEnum.B);

  public static <E extends Enum<E>> ImmutableSet<E> immutableEnumSet(Iterable<E> elements) {
    if (elements instanceof ImmutableEnumSet) {
      return (ImmutableEnumSet<E>) elements;
    } else if (elements instanceof Collection) {
      Collection<E> collection = (Collection<E>) elements;
      if (collection.isEmpty()) {
        return ImmutableSet.of();
      } else {
        return ImmutableEnumSet.asImmutable(EnumSet.copyOf(collection));

        return this;
      }
    }

    ImmutableSet<E> toImmutableSet() {
      if (set == null) {
        return ImmutableSet.of();
      }
      ImmutableSet<E> ret = ImmutableEnumSet.asImmutable(set);
      set = null; // subsequent manual manipulation of the accumulator mustn't affect ret
      return ret;
    }
  }

  @GwtIncompatible
  @SuppressWarnings({"rawtypes", "unchecked"})

        return this;
      }
    }

    ImmutableSet<E> toImmutableSet() {
      if (set == null) {
        return ImmutableSet.of();
      }
      ImmutableSet<E> ret = ImmutableEnumSet.asImmutable(set);
      set = null; // subsequent manual manipulation of the accumulator mustn't affect ret
      return ret;
    }
  }

  @GwtIncompatible
  @SuppressWarnings({"rawtypes", "unchecked"})

    }
  }

  @SuppressWarnings({"rawtypes", "unchecked"}) // necessary to compile against Java 8
  private static ImmutableSet copyOfEnumSet(EnumSet<?> enumSet) {
    return ImmutableEnumSet.asImmutable(EnumSet.copyOf((EnumSet) enumSet));
  }

  ImmutableSet() {}

  /** Returns {@code true} if the {@code hashCode()} method runs quickly. */
  boolean isHashCodeFast() {
    return false;

  }

  ImmutableList<E> createAsList() {
    return ImmutableList.asImmutableList(toArray());
  }

  /*
   * This class is used to serialize all ImmutableSet instances, except for
   * ImmutableEnumSet/ImmutableSortedSet, regardless of implementation type. It
   * captures their "logical contents" and they are reconstructed using public
   * static factories. This is necessary to ensure that the existence of a