* #successors(Object)} and {@link #incidentEdges(Object)}.
   *
   * @since 29.0
   */
  ElementOrder<N> incidentEdgeOrder();

  //
  // Element-level accessors
  //

  /**
   * Returns a live view of the nodes which have an incident edge in common with {@code node} in
   * this graph.
   *
   * <p>This is equal to the union of {@link #predecessors(Object)} and {@link #successors(Object)}.
   *

 *     unless it is constrained by using a method like {@link #nodeOrder}, or the builder is
 *     constructed based on an existing {@code Network} using {@link #from(Network)}.
 * @param <E> The most general edge type this builder will support. This is normally {@code Object}
 *     unless it is constrained by using a method like {@link #edgeOrder}, or the builder is

 *       order)
 * </ul>
 *
 * <p>{@code ValueGraph}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code

 * href="https://github.com/google/guava/issues/2575">Guava issue 2575</a>. TODO: b/283778848 - Fill
 * in CVE number once it's available.)
 *
 * <p>Temporary files created by this stream may live in the local filesystem until either:
 *
 * <ul>
 *   <li>{@link #reset} is called (removing the data in this stream and deleting the file), or...

 *       order)
 * </ul>
 *
 * <p>{@code Graph}s built by this class also guarantee that each collection-returning accessor
 * returns a <b>(live) unmodifiable view</b>; see <a
 * href="https://github.com/google/guava/wiki/GraphsExplained#accessor-behavior">the external
 * documentation</a> for details.
 *
 * <p>Examples of use:
 *
 * <pre>{@code

   * @throws Exception if unable to load the result
   * @throws InterruptedException if this method is interrupted. {@code InterruptedException} is
   *     treated like any other {@code Exception} in all respects except that, when it is caught,
   *     the thread's interrupt status is set
   */
  public abstract V load(K key) throws Exception;

  /**

 *       ordered pair of keys, a row key and column key.
 *   <dt>{@link Multiset}
 *   <dd>An extension of {@link java.util.Collection} that may contain duplicate values like a
 *       {@link java.util.List}, yet has order-independent equality like a {@link java.util.Set}.
 *       One typical use for a multiset is to represent a histogram.
 *   <dt>{@link ClassToInstanceMap}

 * should not fail a test when it does. (The behavior of a {@code TearDown} that throws an exception
 * varies; see its documentation for details.) Use it just like a {@code TearDown}, except override
 * {@link #sloppyTearDown()} instead.
 *
 * @author Luiz-Otavio Zorzella
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

    The problem is that GWT responds poorly to two .gwt.xml files in the same
    Java package; see https://goo.gl/pRV3Yn for details.

    The summary is that it ignores one file in favor of the other.
    util.concurrent, like nearly all our packages, has two .gwt.xml files: one
    for prod and one for tests. However, unlike our other packages, as of this
    writing it has test supersource but no prod supersource.

      return;
    }
    keyToRemove = map.keySet().iterator().next();
    if (supportsRemove) {
      int initialSize = map.size();
      map.get(keyToRemove);
      map.remove(keyToRemove);
      // This line doesn't hold - see the Javadoc comments above.
      // assertEquals(expectedValue, oldValue);
      assertFalse(map.containsKey(keyToRemove));
      assertEquals(initialSize - 1, map.size());
    } else {
      try {