public final V getOrDefault(@CheckForNull Object key, @CheckForNull V defaultValue) {
    /*
     * Even though it's weird to pass a defaultValue that is null, some callers do so. Those who
     * pass a literal "null" should probably just use `get`, but I would expect other callers to
     * pass an expression that *might* be null. This could happen with:
     *
     * - a `getFooOrDefault(@CheckForNull Foo defaultValue)` method that returns

    Iterator<Entry<K, V>> iterator = entrySet.iterator();
    if (supportsIteratorRemove) {
      int initialSize = map.size();
      Entry<K, V> entry = iterator.next();
      Entry<K, V> entryCopy = Helpers.mapEntry(entry.getKey(), entry.getValue());

      iterator.remove();
      assertEquals(initialSize - 1, map.size());

      // Use "entryCopy" instead of "entry" because "entry" might be invalidated after

    return containsKey(key) ? removeFromBothMaps(key) : null;
  }

  @CanIgnoreReturnValue
  @ParametricNullness
  private V removeFromBothMaps(@CheckForNull Object key) {
    // The cast is safe because the callers of this method first check that the key is present.
    V oldValue = uncheckedCastNullableTToT(delegate.remove(key));
    removeFromInverseMap(oldValue);
    return oldValue;
  }

    }
  }

  /*
   * For a discussion of the signature of verifyNotNull, see the discussion above
   * Preconditions.checkNotNull.
   *
   * (verifyNotNull has many fewer "problem" callers, so we could try to be stricter. On the other
   * hand, verifyNotNull arguably has more reason to accept nullable arguments in the first
   * place....)
   */

  /**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.features.CollectionFeature.KNOWN_ORDER;
import static com.google.common.collect.testing.features.CollectionFeature.SERIALIZABLE;

 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.Maps.newHashMap;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.features.CollectionFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.CollectionFeature.SUPPORTS_REMOVE;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.testing.SerializableTester.reserialize;
import static com.google.common.truth.Truth.assertThat;
import static com.google.common.truth.Truth.assertWithMessage;

   * Internal constructor. Users should use {@link PairedStatsAccumulator#snapshot}.
   *
   * <p>To ensure that the created instance obeys its contract, the parameters should satisfy the
   * following constraints. This is the callers responsibility and is not enforced here.
   *
   * <ul>
   *   <li>Both {@code xStats} and {@code yStats} must have the same {@code count}.
   *   <li>If that {@code count} is 1, {@code sumOfProductsOfDeltas} must be exactly 0.0.

    public SampleElements<Entry<Country, Currency>> samples() {
      return new SampleElements<>(
          Helpers.mapEntry(Country.CANADA, Currency.DOLLAR),
          Helpers.mapEntry(Country.CHILE, Currency.PESO),
          Helpers.mapEntry(Country.UK, Currency.POUND),
          Helpers.mapEntry(Country.JAPAN, Currency.YEN),
          Helpers.mapEntry(Country.SWITZERLAND, Currency.FRANC));
    }

    @SuppressWarnings("unchecked")
    @Override

    public SampleElements<Entry<Country, Currency>> samples() {
      return new SampleElements<>(
          Helpers.mapEntry(Country.CANADA, Currency.DOLLAR),
          Helpers.mapEntry(Country.CHILE, Currency.PESO),
          Helpers.mapEntry(Country.UK, Currency.POUND),
          Helpers.mapEntry(Country.JAPAN, Currency.YEN),
          Helpers.mapEntry(Country.SWITZERLAND, Currency.FRANC));
    }

    @SuppressWarnings("unchecked")
    @Override