public void testEmptyMapLast() {
    assertThrows(NoSuchElementException.class, () -> assertNull(navigableMap.lastKey()));
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapLast() {
    assertEquals(a.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(SEVERAL)

 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.SEVERAL;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;

import com.google.common.annotations.GwtCompatible;

    // Now we find the task in our Executor and explicitly activate it.
    List<Runnable> tasks = executor.getTasks();
    assertEquals("One event dispatch task should be queued.", 1, tasks.size());

    tasks.get(0).run();

    assertEquals("One event should be delivered.", 1, events.size());
    assertWithMessage("Correct string should be delivered.").that(events.get(0)).isEqualTo(EVENT);
  }

  /**

import okhttp3.internal.connection.RoutePlanner.Plan
import okhttp3.internal.okHttpName

/**
 * Speculatively connects to each IP address of a target address, returning as soon as one of them
 * connects successfully. This kicks off new attempts every 250 ms until a connect succeeds.
 */
internal class FastFallbackExchangeFinder(
  override val routePlanner: RoutePlanner,

   *
   * @return {@code true} if the graph was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean addNode(N node);

  /**
   * Adds an edge connecting {@code nodeU} to {@code nodeV} if one is not already present, and sets
   * a value for that edge to {@code value} (overwriting the existing value, if any).
   *
   * <p>If the graph is directed, the resultant edge will be directed; otherwise, it will be

            .withFeatures(
                CollectionFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.GENERAL_PURPOSE,
                CollectionFeature.KNOWN_ORDER,
                CollectionSize.ONE,
                CollectionSize.SEVERAL)
            .createTestSuite());
    suite.addTestSuite(TreeMultimapNaturalTest.class);
    return suite;
  }

  protected SetMultimap<String, Integer> create() {

import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_ITERATOR_REMOVE;
import static com.google.common.collect.testing.features.CollectionSize.ONE;
import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;

    Collection<Entry<K, V>> entries = getSampleEntries(getNumEntries() - 1);
    entries.add(entry(null, v3()));
    Map<K, V> other = newHashMap(entries);

    assertFalse(
        "Two Maps should not be equal if exactly one of them contains a null key.",
        getMap().equals(other));
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testEquals_containingNullValue() {

   * {@code requireNonNull}: Our use case is the one in which {@code T} has parametric nullness—and
   * thus its value may be legitimately {@code null}.)
   */
  @ParametricNullness
  @SuppressWarnings("nullness")
  static <T extends @Nullable Object> T uncheckedCastNullableTToT(@Nullable T t) {
    return t;
  }

  /** Returns {@code null} as any type, even one that does not include {@code null}. */