resetContainer(Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v3()));

    Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
    Collection<V> valueCollection = Iterables.getOnlyElement(asMapEntrySet).getValue();
    assertContentsAnyOrder(valueCollection, v0(), v3());
    assertTrue(multimap().put(k0(), v4()));
    assertContentsAnyOrder(valueCollection, v0(), v3(), v4());
  }

  @MultisetFeature.Require(ENTRIES_ARE_VIEWS)
  public void testEntryViewReflectsRemove() {
    initThreeCopies();
    assertEquals(3, getMultiset().count(e0()));
    Multiset.Entry<E> entry = Iterables.getOnlyElement(getMultiset().entrySet());
    assertEquals(3, entry.getCount());
    assertTrue(getMultiset().remove(e0()));
    assertEquals(2, entry.getCount());
    assertTrue(getMultiset().elementSet().remove(e0()));

    Iterable<String> iterable = Collections.singletonList("foo");
    assertEquals("foo", Iterables.getOnlyElement(iterable));
  }

  public void testGetOnlyElement_noDefault_empty() {
    Iterable<String> iterable = Collections.emptyList();
    try {
      Iterables.getOnlyElement(iterable);
      fail();
    } catch (NoSuchElementException expected) {
    }
  }

  @MultisetFeature.Require(ENTRIES_ARE_VIEWS)
  public void testEntryViewReflectsRemove() {
    initThreeCopies();
    assertEquals(3, getMultiset().count(e0()));
    Multiset.Entry<E> entry = Iterables.getOnlyElement(getMultiset().entrySet());
    assertEquals(3, entry.getCount());
    assertTrue(getMultiset().remove(e0()));
    assertEquals(2, entry.getCount());
    assertTrue(getMultiset().elementSet().remove(e0()));

  }

  public void testGetOnlyElement_withDefault_empty() {
    Iterator<String> iterator = Iterators.emptyIterator();
    assertEquals("bar", Iterators.getOnlyElement(iterator, "bar"));
  }

  public void testGetOnlyElement_withDefault_empty_null() {
    Iterator<String> iterator = Iterators.emptyIterator();
    assertNull(Iterators.<@Nullable String>getOnlyElement(iterator, null));

import static com.google.common.base.Preconditions.checkState;
import static com.google.common.collect.CollectPreconditions.checkEntryNotNull;
import static com.google.common.collect.Iterables.getOnlyElement;

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.EnumMap;

 * 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.Iterables.getOnlyElement;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.collect.testing.MapTestSuiteBuilder;
import com.google.common.collect.testing.TestStringMapGenerator;

 * 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.Iterables.getOnlyElement;
import static com.google.common.truth.Truth.assertThat;

import com.google.common.collect.testing.MapTestSuiteBuilder;
import com.google.common.collect.testing.TestStringMapGenerator;

    resetContainer(Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v3()));

    Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
    Collection<V> valueCollection = Iterables.getOnlyElement(asMapEntrySet).getValue();
    assertContentsAnyOrder(valueCollection, v0(), v3());
    assertTrue(multimap().put(k0(), v4()));
    assertContentsAnyOrder(valueCollection, v0(), v3(), v4());
  }

 * 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.Iterables.getOnlyElement;
import static com.google.common.collect.Iterables.unmodifiableIterable;
import static com.google.common.collect.Sets.newHashSet;
import static com.google.common.reflect.Reflection.newProxy;