/**
   * Remove {@code edge} from the set of incoming edges. Returns the former predecessor node.
   *
   * <p>In the undirected case, returns {@code null} if {@code isSelfLoop} is true.
   */
  @CanIgnoreReturnValue
  @CheckForNull
  N removeInEdge(E edge, boolean isSelfLoop);

  /** Remove {@code edge} from the set of outgoing edges. Returns the former successor node. */
  @CanIgnoreReturnValue
  N removeOutEdge(E edge);

  protected void expectMissingValues(V... elements) {
    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  /** @return an array of the proper size with {@code null} as the key of the middle element. */
  protected Entry<K, V>[] createArrayWithNullKey() {
    Entry<K, V>[] array = createSamplesArray();
    int nullKeyLocation = getNullLocation();

        /*
         * NOTE: "invoker:install" vs "appassembler:assemble": Both mojos use the artifact installer to put an artifact
         * into a repository. In the first case, the result needs to be a proper local repository that one can use for
         * local artifact resolution. In the second case, the result needs to precisely obey the path information of the

    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. <b>You are attempting to create a set that may contain a non-{@code Comparable}
   * element.</b> Proper calls will resolve to the version in {@code ImmutableSortedSet}, not this
   * dummy version.
   *
   * @throws UnsupportedOperationException always

import static org.mockito.Mockito.verify;

import java.io.Flushable;
import java.io.IOException;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Flushables}.
 *
 * <p>Checks proper flushing behavior, and ensures that IOExceptions on Flushable.flush() are not
 * propagated out from the {@link Flushables#flush} method if {@code swallowException} is true.
 *
 * @author Michael Lancaster
 */

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import junit.framework.TestCase;

/**
 * Unit tests for {@link Closeables}.
 *
 * <p>Checks proper closing behavior, and ensures that IOExceptions on Closeable.close() are not
 * propagated out from the {@link Closeables#close} method if {@code swallowException} is true.
 *
 * @author Michael Lancaster
 */

 *   <li>remove();
 *   <li>next();
 * </ol>
 *
 * <p>This particular order of operations may be unrealistic, and testing all 3^5 of them may be
 * thought of as overkill; however, it's difficult to determine which proper subset of this massive
 * set would be sufficient to expose any possible bug. Brute force is simpler.
 *
 * <p>To use this class the concrete subclass must implement the {@link

   * collection is empty, but we'd still like to test removeAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRemoveAll_nullCollectionReferenceEmptySubject() {
    try {
      collection.removeAll(null);

    private ArrayWithDuplicate(E[] elements, E duplicate) {
      this.elements = elements;
      this.duplicate = duplicate;
    }
  }

  /**
   * @return an array of the proper size with a duplicate element. The size must be at least three.
   */
  protected ArrayWithDuplicate<E> createArrayWithDuplicateElement() {
    E[] elements = createSamplesArray();

   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_nullCollectionReferenceEmptySubject() {
    try {
      collection.retainAll(null);