Collections.addAll(all, others);
    return copyOf(all.iterator());
  }

  /** ImmutableSet.of API that is friendly to use from JavaScript. */
  @JsMethod(name = "of")
  static <E> ImmutableSet<E> jsOf(E... elements) {
    return copyOf(elements);
  }

  @JsMethod
  public static <E> ImmutableSet<E> copyOf(E[] elements) {
    checkNotNull(elements);
    switch (elements.length) {
      case 0:

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Helper classes and static methods for implementing compact hash-based collections.
 *
 * @author Jon Noack
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class CompactHashing {
  private CompactHashing() {}

  /** Indicates blank table entries. */
  static final byte UNSET = 0;

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Helper classes and static methods for implementing compact hash-based collections.
 *
 * @author Jon Noack
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
final class CompactHashing {
  private CompactHashing() {}

  /** Indicates blank table entries. */
  static final byte UNSET = 0;