assertEmpty(multimap().keys());
    assertEmpty(multimap().values());
    for (K key : sampleKeys()) {
      assertGet(key);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    multimap().clear();
    assertCleared();
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClearThroughEntries() {
    multimap().entries().clear();
    assertCleared();
  }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MapClearTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    getMap().clear();
    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
    assertEquals(0, getMap().size());
    assertFalse(getMap().entrySet().iterator().hasNext());
  }

      assertSame(value, cache.getUnchecked(key));
      assertTrue(cache.asMap().containsKey(key));
      assertTrue(cache.asMap().containsValue(value));
      assertEquals(1, cache.size());
    }
  }

  public void testClear() {
    for (LoadingCache<Key, String> cache : caches()) {
      Key key = new Key(1);
      String value = key.toString();
      assertSame(value, cache.getUnchecked(key));
      assertFalse(cache.asMap().isEmpty());

    }
  }

  protected boolean supportsRemove() {
    return true;
  }

  protected boolean supportsNullValues() {
    return false;
  }

  public void testClear() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    if (supportsRemove()) {
      table.clear();
      assertEquals(0, table.size());
      assertFalse(table.containsRow("foo"));
    } else {

        e.remove();
        assertThat(e.getNext().getElement(), is("3"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testClear() throws Exception {
        list.addLast(null);
        list.addLast("1");
        list.addLast("2");
        list.clear();
        assertThat(list.size(), is(0));

    @Test
    public void testToString() throws Exception {
        assertThat(map.toString(), is(notNullValue()));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testClear() throws Exception {
        map.clear();
        assertThat(map.size(), is(0));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testEntrySet() throws Exception {

   * which are not generally applicable to every instance of Map.
   *
   * @param map the map whose additional invariants to check.
   */
  protected void assertMoreInvariants(Map<K, V> map) {}

  public void testClear() {
    Map<K, V> map;
    try {
      map = makePopulatedMap();
    } catch (UnsupportedOperationException e) {
      return;
    }

    if (supportsClear) {
      map.clear();

      assertThrows(IllegalArgumentException.class, () -> IntMath.binomial(n, 0));
    }
  }

  @AndroidIncompatible // slow
  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1 << 30) - 1, -1, Integer.MAX_VALUE);

    }
    // Should overflow without throwing.
    accumulator.addAll(accumulator.snapshot());
    assertThat(accumulator.count()).isLessThan(0L);
  }

  public void testMean() {
    assertThrows(IllegalStateException.class, () -> emptyAccumulator.mean());
    assertThrows(IllegalStateException.class, () -> emptyAccumulatorByAddAllEmptyIterable.mean());

    long sqrtMaxLong = (long) Math.sqrt(Long.MAX_VALUE);
    assertTrue(sqrtMaxLong <= LongMath.FLOOR_SQRT_MAX_LONG);
  }

  @AndroidIncompatible // slow
  @GwtIncompatible // java.math.BigInteger
  public void testMean() {
    // Odd-sized ranges have an obvious mean
    assertMean(2, 1, 3);

    assertMean(-2, -3, -1);
    assertMean(0, -1, 1);
    assertMean(1, -1, 3);
    assertMean((1L << 62) - 1, -1, Long.MAX_VALUE);