static <E extends @Nullable Object> boolean addAllImpl(
      Multiset<E> self, Collection<? extends E> elements) {
    checkNotNull(self);
    checkNotNull(elements);
    if (elements instanceof Multiset) {
      return addAllImpl(self, cast(elements));
    } else if (elements.isEmpty()) {
      return false;
    } else {
      return Iterators.addAll(self, elements.iterator());
    }
  }

    try {
      // any ClassCastExceptions and NullPointerExceptions are caught
      @SuppressWarnings({"unchecked", "nullness"})
      SortedSet<@Nullable Object> self = (SortedSet<@Nullable Object>) this;
      Object ceiling = self.tailSet(object).first();
      return unsafeCompare(comparator(), ceiling, object) == 0;
    } catch (ClassCastException | NoSuchElementException | NullPointerException e) {
      return false;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;
import static com.google.common.graph.GraphConstants.SELF_LOOPS_NOT_ALLOWED;
import static com.google.common.graph.Graphs.checkNonNegative;
import static com.google.common.graph.Graphs.checkPositive;
import static java.util.Objects.requireNonNull;

    this.allowsParallelEdges = allowsParallelEdges;
    return this;
  }

  /**
   * Specifies whether the network will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a network that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * <p>The default value is {@code false}.
   */
  @CanIgnoreReturnValue

   * @param self a collection which might contain all elements in {@code c}
   * @param c a collection whose elements might be contained by {@code self}
   */
  static boolean containsAllImpl(Collection<?> self, Collection<?> c) {
    for (Object o : c) {
      if (!self.contains(o)) {
        return false;
      }
    }
    return true;
  }

  /** An implementation of {@link Collection#toString()}. */

        "containsAll(sameElements) should return true",
        collection.containsAll(MinimalCollection.of(createSamplesArray())));
  }

  @SuppressWarnings("ModifyingCollectionWithItself")
  public void testContainsAll_self() {
    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(

      createDirectedGraph("ab", "ac", "bd", "cd");

  /**
   * Same as {@link #DIAMOND_GRAPH}, but with an extra c->a edge and some self edges:
   *
   * <pre>{@code
   *   a<>
   *  / \\
   * b   c
   *  \ /
   *   d<>
   * }</pre>
   *
   * {@code <>} indicates a self-loop
   */
  private static final SuccessorsFunction<Character> MULTI_GRAPH =
      createDirectedGraph("aa", "dd", "ab", "ac", "ca", "cd", "bd");

      Pray, what is the reason of that?'

    `In my youth,' said the sage, as he shook his grey locks,
      `I kept all my limbs very supple
    By the use of this ointment--one shilling the box--
      Allow me to sell you a couple?'

    `You are old,' said the youth, `and your jaws are too weak
      For anything tougher than suet;
    Yet you finished the goose, with the bones and the beak--

import static com.google.common.graph.GraphConstants.PARALLEL_EDGES_NOT_ALLOWED;
import static com.google.common.graph.GraphConstants.REUSING_EDGE;
import static com.google.common.graph.GraphConstants.SELF_LOOPS_NOT_ALLOWED;
import static java.util.Objects.requireNonNull;

import com.google.common.collect.ImmutableList;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/**

public class CollectionEqualsTester<E> extends AbstractCollectionTester<E> {

  // TODO(cpovirk): Consider using EqualsTester from Guava.
  @SuppressWarnings("SelfEquals")
  public void testEquals_self() {
    assertTrue("An Object should be equal to itself.", collection.equals(collection));
  }

  public void testEquals_null() {
    // noinspection ObjectEqualsNull