/**
   * Returns the entry of the first element in this multiset, or {@code null} if this multiset is
   * empty.
   */
  @CheckForNull
  Entry<E> firstEntry();

  /**
   * Returns the entry of the last element in this multiset, or {@code null} if this multiset is
   * empty.
   */
  @CheckForNull
  Entry<E> lastEntry();

  /**

@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Runnables {

  private static final Runnable EMPTY_RUNNABLE =
      new Runnable() {
        @Override
        public void run() {}
      };

  /** Returns a {@link Runnable} instance that does nothing when run. */
  public static Runnable doNothing() {
    return EMPTY_RUNNABLE;
  }

  private Runnables() {}

  static final RegularImmutableBiMap<Object, Object> EMPTY =
      new RegularImmutableBiMap<Object, Object>();

  // This reference is used both by the GWT compiler to infer the elements
  // of the lists that needs to be serialized.
  private ImmutableBiMap<V, K> inverse;

  @SuppressWarnings("unchecked") // used only for the empty map, which works for any types
  RegularImmutableBiMap() {

    // occur in practice.
    if (safeMin >= Character.MIN_HIGH_SURROGATE) {
      // The safe range is empty or the all safe code points lie in or above the
      // surrogate range. Either way the character range is empty.
      this.safeMinChar = Character.MAX_VALUE;
      this.safeMaxChar = 0;
    } else {
      // The safe range is non-empty and contains values below the surrogate

   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
   * Equality does not depend on the ordering of keys or values.
   *
   * <p>An empty {@code SetMultimap} is equal to any other empty {@code Multimap}, including an
   * empty {@code ListMultimap}.
   */
  @Override
  boolean equals(@CheckForNull Object obj);

@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class CollectionContainsAllTester<E> extends AbstractCollectionTester<E> {
  public void testContainsAll_empty() {
    assertTrue(
        "containsAll(empty) should return true", collection.containsAll(MinimalCollection.of()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAll_subset() {
    assertTrue(

    }

    private static final long serialVersionUID = 0;
  }

  /** Creates an empty {@code HashBasedTable}. */
  public static <R, C, V> HashBasedTable<R, C, V> create() {
    return new HashBasedTable<>(new LinkedHashMap<R, Map<C, V>>(), new Factory<C, V>(0));
  }

  /**
   * Creates an empty {@code HashBasedTable} with the specified map sizes.
   *

    for (int c = chars.nextSetBit(0); c != -1; c = chars.nextSetBit(c + 1)) {
      // Compute the filter at the same time.
      filter |= 1L << c;
      int index = smear(c) & mask;
      while (true) {
        // Check for empty.
        if (table[index] == 0) {
          table[index] = (char) c;
          break;
        }
        // Linear probing.
        index = (index + 1) & mask;
      }
    }

    assertEquals(1, ms.count(Color.YELLOW));
    assertEquals(2, ms.count(Color.RED));
  }

  public void testIllegalCreate() {
    Collection<Color> empty = EnumSet.noneOf(Color.class);
    try {
      EnumMultiset.create(empty);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testCreateEmptyWithClass() {

    }
  }

  // Following Javadoc copied from Multimap and SortedSetMultimap.

  /**
   * Returns a collection view of all values associated with a key. If no mappings in the multimap
   * have the provided key, an empty collection is returned.
   *
   * <p>Changes to the returned collection will update the underlying multimap, and vice versa.
   *
   * <p>Because a {@code SortedSetMultimap} has unique sorted values for a given key, this method